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1.
Eur J Vasc Endovasc Surg ; 67(4): 570-582, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38013062

RESUMEN

OBJECTIVE: Large abdominal aortic aneurysms (AAAs) present a significant mortality risk. While numerous medical interventions have been proposed, no drugs have convincingly reduced AAA progression, rupture rates, or repair risk. This systematic review and meta-analysis aimed to assess the impact of re-purposed drugs or dietary supplements on slowing expansion rates, reducing the risk of rupture, or minimising the risk of repair for individuals with AAA. METHODS: A systematic search was conducted in five databases. Both observational studies and randomised controlled trials were included. Unpublished data from two screening trials were incorporated. Risk of bias was assessed using the Newcastle-Ottawa scale and revised Cochrane risk of bias tool. Meta-analyses were performed for each identified drug subclass and were stratified by overall risk of bias. Results were reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: Of 7 484 screened studies, 39 met the inclusion criteria. No studies on dietary supplements were included. A total of 84 cohorts were derived from the included studies, and twelve distinct drug groups underwent meta-analyses. Two drug groups, metformin and statins, were statistically significant in slowing AAA growth. No low risk of bias studies were included for these two drug groups, and the results had very high heterogeneity (I2 > 80%). Both groups had a GRADE certainty of very low. Metformin, excluding high risk of bias studies, presented an estimated mean growth difference of AAA diameter between users and non-users of -0.73 mm/year, whilst statins had an overall estimated mean difference of -0.84 mm/year. CONCLUSION: This systematic review and meta-analysis suggests that metformin and statins may provide some effect in slowing AAA progression. However, no definitive evidence was found for any of the investigated drugs included in this study. Further research is needed to identify effective medical treatments for AAA progression with more robust methodology.


Asunto(s)
Aneurisma de la Aorta Abdominal , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Metformina , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Aneurisma de la Aorta Abdominal/tratamiento farmacológico
2.
Ann Vasc Surg ; 91: 127-134, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36563844

RESUMEN

BACKGROUND: To investigate if a relative-size-index of the abdominal aortic diameter influences the prevalence estimates of abdominal aortic dilatations compared to absolute diameters. METHODS: Cross-sectional study. Participants from the Viborg Vascular Screening Trial, Viborg Women Cohort, and the Viborg Screening Program. Through multivariate linear regression analyses, 2 gender-specific prediction-equations were developed based upon body-surface area and age. The definitions of absolute and relative size of aortic ectasies were 25-29 mm and 1.25-1.49× individual-predicted size (IPS), abdominal aortic aneurysm (AAA) 30 mm and 1.5× IPS, and large repair-recommendable AAA ≥55 mm or ≥ 2.75× IPS, respectively. RESULTS: Nineteen thousand two hundred and sixty nine males (69.6 years) and 2,426 females (67.1 years) attended the population- and ultrasound-based screening studies for AAA. The mean peak systolic abdominal anterior-posterior inner to inner diameter was 19.1 mm (±5.3 mm) and 16.6 mm (±2.8 mm) (P < 0.001) in males and females, respectively. Body surface area showed the strongest correlation with aortic diameters in both males (r = 0.19, P < 0.001) and females (r = 0.17, P < 0.001). Age correlated significantly with size, but only in males (r = 0.03, P < 0.001). The prevalence in men of absolute size-defined and relative size index-defined screening-detected aortic ectasies, AAAs and repair-recommendable AAAs were: 5.9% and 9.5% (P < 0.001), 3.3% and 4.2% (P < 0.001) and 9.9% and 15.2% (P = 0.004), respectively. Prevalence in females of absolute-size-defined and relative-size-index-defined screening-detected aortic ectasies, AAAs and repair-recommendable AAAs were 1.2% and 5.8% (P < 0.001), 0.5% and 1.3% (P = 0.003) and 0.0% and 23.1% (P = 0.553), respectively. CONCLUSIONS: Despite statistical differences, ultrasound-based absolute diameters to detect AAA seem acceptable in men. In females, poor agreements were noticed concerning all 3 categories of aneurysms, indicating that the current absolute diagnostic cut-points do not reflect female anatomy.


Asunto(s)
Aneurisma de la Aorta Abdominal , Tamizaje Masivo , Masculino , Humanos , Femenino , Prevalencia , Estudios Transversales , Resultado del Tratamiento , Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Aneurisma de la Aorta Abdominal/epidemiología , Factores de Riesgo
3.
Scand J Med Sci Sports ; 32(6): 1013-1025, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35305276

RESUMEN

The study aimed to investigate the effectiveness of an individualized power training program based on force-velocity (FV) profiling on physical function, muscle morphology, and neuromuscular adaptations in older men. Forty-nine healthy men (68 ± 5 years) completed a 10-week training period to enhance muscular power. They were randomized to either a generic power training group (GPT) or an individualized power training group (IPT). Unlike generic training, individualized training was based on low- or high-resistance exercises, from an initial force-velocity profile. Lower-limb FV profile was measured in a pneumatic leg-press, and physical function was assessed as timed up-and-go time (TUG), sit-to-stand power, grip strength, and stair-climbing time (loaded [20kg] and unloaded). Vastus lateralis morphology was measured with ultrasonography. Rate of force development (RFD) and rate of myoelectric activity (RMA) were measured during an isometric knee extension. The GPT group improved loaded stair-climbing time (6.3 ± 3.8 vs. 2.3% ± 7.3%, p = 0.04) more than IPT. Both groups improved stair-climbing time, sit to stand, and leg press power, grip strength, muscle thickness, pennation angle, fascicle length, and RMA from baseline (p < 0.05). Only GPT increased loaded stair-climbing time and RFD (p < 0.05). An individualized power training program based on FV profiling did not improve physical function to a greater degree than generic power training. A generic power training approach combining both heavy and low loads might be advantageous through eliciting both force- and velocity-related neuromuscular adaptions with a concomitant increase in muscular power and physical function in older men.


Asunto(s)
Fuerza Muscular , Entrenamiento de Fuerza , Adaptación Fisiológica , Anciano , Prueba de Esfuerzo , Humanos , Masculino , Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Músculo Cuádriceps/diagnóstico por imagen
4.
Eur J Vasc Endovasc Surg ; 62(2): 267-274, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33947618

RESUMEN

OBJECTIVE: Inactivation of matrix Gla protein (MGP), using vitamin K antagonists or vitamin K deficiency results in increased vascular calcification, which has been associated with increased risk of symptomatic or ruptured abdominal aortic aneurysm (AAA). Insufficient activation of MGP leads to increased levels of undercarboxylated forms of MGP, measured as a dephosphorylated, undercarboxylated MGP (dp-ucMGP) in plasma. This study aimed to investigate whether the level of inactivated MGP influenced the risk of having an AAA, the risk of AAA progression, and overall mortality. METHODS: This combined case control and cohort study was based on data from the randomised, clinically controlled Viborg Vascular (VIVA) screening trial. Cases (n = 487) with an AAA and controls (n = 189) with neither peripheral artery disease nor AAA, had their plasma quantified for dp-ucMGP. Plasma levels were compared with the presence of an AAA, AAA growth rate, need for repair, and overall mortality. dp-ucMGP was divided into tertiles in regression analyses. RESULTS: The plasma levels of dp-ucMGP were higher for AAA cases compared with controls (median of 517 pmol/L vs. 495 pmol/L, p = .036). Adjusted analyses regarding dp-ucMGP being predictive of AAA, AAA growth rate, and need for repair all failed to show correlation. Overall mortality for AAA cases exhibited a significant association for the third tertile of dp-ucMGP with a hazard ratio of 2.55 (95% CI 1.29 - 5.05) compared with the first tertile. Overall mortality for controls was not correlated with dp-ucMGP plasma levels. CONCLUSION: dp-ucMGP did not correlate with the risk of having an AAA, AAA growth rate, or risk of surgery. For people with an AAA, dp-ucMGP was correlated with an increased mortality risk for the highest tertile of dp-ucMGP. This could suggest a role for prophylactic measures with vitamin K2 supplements to people at risk of AAA.


Asunto(s)
Aneurisma de la Aorta Abdominal/sangre , Aneurisma de la Aorta Abdominal/mortalidad , Proteínas de Unión al Calcio/sangre , Progresión de la Enfermedad , Proteínas de la Matriz Extracelular/sangre , Anciano , Aneurisma de la Aorta Abdominal/cirugía , Estudios de Casos y Controles , Estudios de Cohortes , Humanos , Masculino , Ensayos Clínicos Controlados Aleatorios como Asunto , Vitamina K/antagonistas & inhibidores , Proteína Gla de la Matriz
5.
Eur J Vasc Endovasc Surg ; 61(3): 502-509, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33309171

RESUMEN

OBJECTIVE: The aim of this study was to systematically review the literature and give evidence based recommendations for future initiatives for simulation based training (SBT) and assessment in open vascular surgery. DATA SOURCES: PubMed, Embase, and the Cochrane Library. REVIEW METHODS: A systematic review of PubMed, Embase, and the Cochrane Library was performed, with the last search on 31 March 2020, to identify studies describing SBT and assessment in open vascular surgery. Kirkpatrick's levels for efficacy of training were evaluated. Validity evidence for assessment tools was evaluated according to the recommended contemporary framework by Messick. RESULTS: Of 2 844 studies, 51 were included for data extraction. A high degree of heterogeneity in reporting standards and varying types of simulation was found. Vascular anastomosis was the most frequently simulated technical skill (43%). Assessment was mostly carried out using the Objective Structured Assessment of Technical Skills (55%). Validity evidence for assessment tools was found using outdated frameworks, and only one study used Messick's framework. Self directed training is valuable, the low trainer to trainee ratio is important to maximise efficiency, and experienced vascular surgeons are the most effective trainers. CONCLUSION: Carefully designed and structured SBT is effective and can improve technical skills, especially in less experienced trainees. However, the supporting evidence lacks homogeneity in the reporting standards and types of simulations. Pass/fail standards that support proficiency based learning and studies investigating skills transfer should be the focus in future studies. Validity evidence of assessment tools needs to be addressed using contemporary frameworks.


Asunto(s)
Educación de Postgrado en Medicina , Entrenamiento Simulado , Cirujanos/educación , Procedimientos Quirúrgicos Vasculares/educación , Competencia Clínica , Humanos , Curva de Aprendizaje
6.
Ecotoxicol Environ Saf ; 211: 111812, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33472112

RESUMEN

Due to the potential hazard of diclofenac on aquatic organisms and the lack of higher-tier ecotoxicological studies, a long-term freshwater mesocosm experiment was set up to study the effects of this substance on primary producers and consumers at environmentally realistic nominal concentrations 0.1, 1 and 10 µg/L (average effective concentrations 0.041, 0.44 and 3.82 µg/L). During the six-month exposure period, the biovolume of two macrophyte species (Nasturtium officinale and Callitriche platycarpa) significantly decreased at the highest treatment level. Subsequently, a decrease in dissolved oxygen levels was observed. High mortality rates, effects on immunity, and high genotoxicity were found for encaged zebra mussels (Dreissena polymorpha) in all treatments. In the highest treatment level, one month after the beginning of the exposure, mortality of adult fish (Gasterosteus aculeatus) caused effects on the final population structure. Total abundance of fish and the percentage of juveniles decreased whereas the percentage of adults increased. This led to an overall shift in the length frequency distribution of the F1 generation compared to the control. Consequently, indirect effects on the community structure of zooplankton and macroinvertebrates were observed in the highest treatment level. The No Observed Effect Concentration (NOEC) value at the individual level was < 0.1 µg/L and 1 µg/L at the population and community levels. Our study showed that in more natural conditions, diclofenac could cause more severe effects compared to those observed in laboratory conditions. The use of our results for regulatory matters is also discussed.


Asunto(s)
Organismos Acuáticos/fisiología , Diclofenaco/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Dreissena/efectos de los fármacos , Peces , Agua Dulce/química , Especies Centinela , Smegmamorpha , Zooplancton/efectos de los fármacos
7.
Cephalalgia ; 40(10): 1045-1054, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32806954

RESUMEN

INTRODUCTION: Administration of ATP-sensitive potassium channel opener levcromakalim triggers headache in healthy volunteers and migraine attacks in migraine patients. Here, we investigated the effect of ATP-sensitive potassium channel blocker glibenclamide on levcromakalim-induced headache in healthy volunteers. METHODS: In a randomized, double-blind, placebo-controlled, three-way cross-over study, 15 healthy volunteers aged 18-40 years were randomly allocated to receive glibenclamide and levcromakalim (day 1), glibenclamide and placebo (day 2), and placebo and placebo (day 3) on three different days separated by at least 1 week. The primary endpoints were the difference in incidence of headache and the difference in area under the curve for headache intensity scores (0-12 hours) between the days. RESULTS: Fifteen healthy volunteers completed the 3 days of the study. More participants (12/15, 80%) developed headache on the glibenclamide-levcromakalim day compared to the glibenclamide-placebo day (5/15, 33%) (p = 0.01; mean difference 47%; 95% confidence interval 18-75%) and compared to the placebo-placebo day (1/15, 7%) (p = 0.001; mean difference 73%; 95% confidence interval 48-99%). We found no difference in headache incidence between glibenclamide-placebo day and placebo-placebo day (p = 0.12; mean difference 27%; 95% confidence interval 1.3-52%). The area under the curve for headache intensity was significantly larger on the glibenclamide-levcromakalim day compared to the glibenclamide-placebo day (p = 0.003); and compared to the placebo-placebo day (p = 0.001). We found no difference in the area under the curve between the glibenclamide-placebo day compared to the placebo-placebo day (p = 0.07). The median time to onset for headache after levcromakalim infusion with glibenclamide pretreatment was delayed (180 min) compared to levcromakalim without pretreatment (30 min) from a previously published study. CONCLUSION: Glibenclamide administration did not cause headache, and glibenclamide pretreatment did not prevent levcromakalim-induced headache. However, glibenclamide delayed the onset of levcromakalim-induced headache. More selective blockers are needed to further elucidate the role of the ATP-sensitive potassium channel in headache initiation.Trial Registration: ClinicalTrials.gov NCT03886922.


Asunto(s)
Analgésicos/farmacología , Cromakalim/efectos adversos , Gliburida/farmacología , Cefalea/inducido químicamente , Vasodilatadores/efectos adversos , Adulto , Estudios Cruzados , Método Doble Ciego , Femenino , Voluntarios Sanos , Humanos , Masculino , Adulto Joven
8.
Rev Med Liege ; 75(11): 699-702, 2020 Nov.
Artículo en Francés | MEDLINE | ID: mdl-33155441

RESUMEN

Venlafaxine is a widely prescribed antidepressant drug acting as a reuptake inhibitor of serotonin and noradrenaline. An overdose of venlafaxine can cause cardiovascular toxicity and cardiogenic shock can occur. A 32-year-old man ingested 12g of sustained-release venlafaxine in a suicidal attempt and developed within 24h acute heart failure with refractory cardiogenic shock requiring support by ECMO. The blood toxicology showed persistence of high levels of venlafaxine at day 10. The patient fully recovered and showed normal cardiac function at 3-months follow-up.


La venlafaxine est un antidépresseur largement prescrit agissant comme inhibiteur de recapture de la sérotonine et de la noradrénaline. Un surdosage en venlafaxine peut engendrer une toxicité cardiovasculaire allant jusqu'à l'état de choc cardiogénique. Un homme de 32 ans a ingéré 12 g de venlafaxine sous une forme à libération prolongée dans une tentative de suicide et a développé en 24 heures une insuffisance cardiaque aiguë avec choc cardiogénique réfractaire nécessitant un support hémodynamique par ECMO. La toxicologie sanguine a montré la persistance de niveaux élevés de venlafaxine au jour 10. Le patient s'est ensuite complètement rétabli et présentait une fonction cardiaque normale 3 mois après l'épisode.


Asunto(s)
Sobredosis de Droga , Oxigenación por Membrana Extracorpórea , Insuficiencia Cardíaca , Adulto , Sobredosis de Droga/complicaciones , Sobredosis de Droga/terapia , Humanos , Masculino , Choque Cardiogénico/inducido químicamente , Choque Cardiogénico/terapia , Clorhidrato de Venlafaxina
9.
Glycobiology ; 28(7): 542-549, 2018 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-29596681

RESUMEN

Precise gene editing technologies are providing new opportunities to stably engineer host cells for recombinant production of therapeutic glycoproteins with different glycan structures. The glycosylation of recombinant therapeutics has long been a focus for both quality and consistency of products and for optimizing and improving pharmacokinetic properties as well as bioactivity. Structures of glycans on therapeutic glycoproteins are important for circulation, biodistribution and bioactivity. In particular, the latter has been demonstrated for therapeutic IgG1 antibodies where the core α1,6Fucose on the conserved N-glycan at Asn297 have remarkable dampening effects on antibody effector functions. We previously explored precise gene engineering and design options for N-glycosylation in CHO cells, and here we focus on engineering options possible for N-glycans on human IgG1. We demonstrate stable precise gene engineering of rather homogenous biantennary N-glycans with and without galactose (G0F, G2F) as well as the α2,6-linked monosialylated (G2FS1) glycoform. We were unable to introduce substantial disialylated glycoforms. Instead we engineered a novel monoantennary homogeneous N-glycan design with complete α2,6-linked sialic acid capping. All N-glycoforms may be engineered with and without core α1,6Fucose. The stably engineered design options enable production of human IgG antibodies with an array of distinct glycoforms for testing and selection of optimal design for different therapeutic applications.


Asunto(s)
Edición Génica/métodos , Inmunoglobulina G/genética , Procesamiento Proteico-Postraduccional , Animales , Células CHO , Cricetinae , Cricetulus , Glicosilación , Humanos , Inmunoglobulina G/química , Inmunoglobulina G/metabolismo , Polisacáridos/metabolismo
10.
Small ; 14(16): e1703338, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29356378

RESUMEN

Development of efficient, affordable, and sustainable energy storage technologies has become an area of interest due to the worsening environmental issues and rising technological dependence on Li-ion batteries. Na-ion batteries (NIBs) have been receiving intensive research efforts during the last few years. Owing to their potentially low cost and relatively high energy density, NIBs are promising energy storage devices, especially for stationary applications. A fundamental understanding of electrode properties during electrochemical reactions is important for the development of low cost, high-energy density, and long shelf life NIBs. This Review aims to summarize and discuss reaction mechanisms of the major types of NIB electrode materials reported. By appreciating how the material works and the fundamental flaws it possesses, it is hoped that this Review will assist readers in coming up with innovative solutions for designing better materials for NIBs.

11.
Klin Monbl Augenheilkd ; 235(5): 597-602, 2018 May.
Artículo en Alemán | MEDLINE | ID: mdl-28147407

RESUMEN

Dry eye disease is one of the most common diagnoses in ophthalmology. A variety of subjective and objective test methods with imprecise limits and highly different sensitivities and specificities complicate the diagnosis. Especially mild to moderate pathological findings can be misdiagnosed. In recent years, new options have opened, through the development of new, clinical practicable diagnostic equipment, for example, for the analysis of tear film osmolarity or matrix metalloproteinases (MMP-9). The value of tear film osmolarity and determination of MMP-9 levels in the diagnosis of dry eye and its subtypes will be discussed and evaluated objectively, on the basis of published study results.


Asunto(s)
Síndromes de Ojo Seco , Metaloproteinasa 9 de la Matriz/análisis , Metaloproteinasas de la Matriz , Síndromes de Ojo Seco/diagnóstico , Humanos , Concentración Osmolar , Sensibilidad y Especificidad , Lágrimas/química
12.
Exp Eye Res ; 155: 107-120, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28089775

RESUMEN

In order to understand the pathological processes of retinal diseases, experimental models are necessary. Cobalt, as part of the vitamin B12 complex, is important for neuronal integrity. However, it is known that high quantities of cobalt induce cytotoxic mechanisms via hypoxia mimicry. Therefore, we tested the degenerative effect of cobalt chloride (CoCl2) on neurons and microglia in a porcine retina organ culture model. Organotypic cultures of porcine retinas were cultured and treated with different concentrations of CoCl2 (0, 100, 300 and 500 µM) for 48 h. After four and eight days, CoCl2 induced a strong degeneration of the porcine retina, starting at 300 µM. A loss of retinal ganglion cells (RGCs, Brn-3a), amacrine cells (calretinin) and bipolar cells (PKCα) was observed. Additionally, a high expression of hypoxia induced factor-1a (HIF-1a) and heat shock protein 70 (HSP70) was noted at both points in time. Also, the Caspase 3 protein was activated and P21 expression was induced. However, only at day four, the Bax/Bcl-2 ratio was increased. The effect of CoCl2 was not restricted to neurons. CoCl2 concentrations reduced the microglia amount (Iba1) and activity (Iba1 + Fcγ-Receptor) at both points in time. These damaging effects on microglia were surprising, since CoCl2 causes hypoxia and a pro-inflammatory environment. However, high concentrations of CoCl2 also seem to be toxic to these cells. Similar degenerative mechanisms as in comparison to retinal ischemia animal models were observed. In summary, an effective and reproducible hypoxia-mimicking organotypic model for retinal degeneration was established, which is easy to handle and ready for drug studies.


Asunto(s)
Cobalto/efectos adversos , Regulación de la Expresión Génica , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Microglía/patología , Degeneración Retiniana/inducido químicamente , Células Ganglionares de la Retina/metabolismo , Neuronas Retinianas/patología , Animales , Antimutagênicos/efectos adversos , Apoptosis , Western Blotting , Supervivencia Celular , Modelos Animales de Enfermedad , Subunidad alfa del Factor 1 Inducible por Hipoxia/biosíntesis , Inmunohistoquímica , Microglía/efectos de los fármacos , Microglía/metabolismo , Técnicas de Cultivo de Órganos , ARN/genética , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Degeneración Retiniana/metabolismo , Degeneración Retiniana/patología , Células Ganglionares de la Retina/efectos de los fármacos , Células Ganglionares de la Retina/patología , Neuronas Retinianas/efectos de los fármacos , Neuronas Retinianas/metabolismo , Porcinos
13.
Mol Pharm ; 11(7): 2182-9, 2014 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-24842574

RESUMEN

Three-dimensional (3D) cell culture has become increasingly adopted as a more accurate model of the complex in vivo microenvironment compared to conventional two-dimensional (2D) cell culture. Multicellular spheroids are important 3D cell culture models widely used in biological studies and drug screening. To facilitate simple spheroid manipulation, magnetic spheroids were generated from magnetically labeled cells using a scaffold-free approach. This method is applicable to a variety of cell types. The spheroids generated can be targeted and immobilized using magnetic field gradients, allowing media change or dilution to be performed with minimal disruption to the spheroids. Cells in magnetic spheroids showed good viability and displayed typical 3D morphology. Using this platform, a 28 day study was carried out using doxorubicin on magnetic MCF-7 spheroids. The results provided a proof-of-principle for using magnetic tumor spheroids in therapeutic studies. They can offer beneficial insights that help to bridge the gap between in vitro and in vivo models. Furthermore, this platform can be adapted for high-throughput screening in drug discovery.


Asunto(s)
Técnicas de Cultivo de Célula/métodos , Evaluación Preclínica de Medicamentos/métodos , Magnetismo/métodos , Esferoides Celulares/fisiología , Antineoplásicos/farmacología , Línea Celular , Línea Celular Tumoral , Doxorrubicina/farmacología , Descubrimiento de Drogas/métodos , Células HCT116 , Células HEK293 , Células HeLa , Humanos , Células MCF-7 , Fenómenos Magnéticos , Esferoides Celulares/efectos de los fármacos
14.
Angew Chem Int Ed Engl ; 53(48): 13229-33, 2014 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-25258104

RESUMEN

Cyclopentenones are versatile structural motifs of natural products as well as reactive synthetic intermediates. The nickel-catalyzed reductive [3+2] cycloaddition of α,ß-unsaturated aromatic esters and alkynes constitutes an efficient method for their synthesis. Here, nickel(0) catalysts comprising a chiral bulky C1-symmetric N-heterocyclic carbene ligand were shown to enable an efficient asymmetric synthesis of cyclopentenones from mesityl enoates and internal alkynes under mild conditions. The bulky NHC ligand provided the cyclopentenone products in very high enantioselectivity and led to a regioselective incorporation of unsymmetrically substituted alkynes.


Asunto(s)
Alquinos/química , Ciclopentanos/química , Níquel/química , Catálisis , Ligandos , Estructura Molecular , Estereoisomerismo
15.
Protein Eng Des Sel ; 372024 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-38713696

RESUMEN

Plastic degrading enzymes have immense potential for use in industrial applications. Protein engineering efforts over the last decade have resulted in considerable enhancement of many properties of these enzymes. Directed evolution, a protein engineering approach that mimics the natural process of evolution in a laboratory, has been particularly useful in overcoming some of the challenges of structure-based protein engineering. For example, directed evolution has been used to improve the catalytic activity and thermostability of polyethylene terephthalate (PET)-degrading enzymes, although its use for the improvement of other desirable properties, such as solvent tolerance, has been less studied. In this review, we aim to identify some of the knowledge gaps and current challenges, and highlight recent studies related to the directed evolution of plastic-degrading enzymes.


Asunto(s)
Evolución Molecular Dirigida , Ingeniería de Proteínas , Evolución Molecular Dirigida/métodos , Plásticos/química , Plásticos/metabolismo , Tereftalatos Polietilenos/química , Tereftalatos Polietilenos/metabolismo , Enzimas/genética , Enzimas/química , Enzimas/metabolismo
16.
J Mater Sci Mater Med ; 24(8): 2013-27, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23670603

RESUMEN

Mechanical properties of collagen films are less than ideal for biomaterial development towards musculoskeletal repair or cardiovascular applications. Herein, we present a collagen-cellulose composite film (CCCF) compared against swine small intestine submucosa in regards to mechanical properties, cell growth, and histological analysis. CCCF was additionally characterized by FE-SEM, NMR, mass spectrometry, and Raman Microscopy to elucidate its physical structure, collagen-cellulose composition, and structure activity relationships. Mechanical properties of the CCCF were tested in both wet and dry environments, with anisotropic stress-strain curves that mimicked soft-tissue. Mesenchymal stem cells, human umbilical vein endothelial cells, and human coronary artery smooth muscle cells were able to proliferate on the collagen films with specific cell orientation. Mesenchymal stem cells had a higher proliferation index and were able to infiltrate CCCF to a higher degree than small intestine submucosa. With the underlying biological properties, we present a collagen-cellulose composite film towards forthcoming biomaterial-related applications.


Asunto(s)
Celulosa/química , Colágeno/química , Tejido Conectivo , Membranas Artificiales , Células Madre Mesenquimatosas/fisiología , Animales , Materiales Biomiméticos/síntesis química , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Polaridad Celular/efectos de los fármacos , Polaridad Celular/fisiología , Células Cultivadas , Celulosa/farmacología , Colágeno/farmacología , Células Endoteliales de la Vena Umbilical Humana/citología , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/fisiología , Humanos , Ensayo de Materiales , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Ratones , Nanofibras/química , Ingeniería de Tejidos/instrumentación , Ingeniería de Tejidos/métodos , Andamios del Tejido/química
17.
Artículo en Inglés | MEDLINE | ID: mdl-37998301

RESUMEN

BACKGROUND: It is well-established that cross-sectional measurements of poor body composition are associated with impaired physical function and that power training effectively enhances total lean mass and physical function in older adults. However, it is unclear if power training-induced changes in body composition are associated with improved physical function in older adults. AIM: The present study investigated associations between body composition and physical function cross-sectionally and with power training-induced changes in older men. METHODS: Forty-nine older men (68 ± 5 yrs) completed a 10-week biweekly power training intervention. Body composition was measured using dual-energy X-ray absorptiometry. Physical function was assessed as a composite Z-score combining measures from Sit-to-stand power, Timed up-and-go time, and loaded and unloaded Stair-climbing time (15 steps). Linear and quadratic regression analyses were performed to assess associations between body composition and physical function. RESULTS: At baseline, total (R2 = 0.11, p < 0.05) and percentage body fat (R2 = 0.15, p < 0.05) showed a non-linear relationship with physical function. The apex of the quadratic regression for body composition was 21.5% body fat. Furthermore, there was a non-linear relationship between changes in body fat percentage and physical function from pre- to post-intervention (R2 = 0.15, p < 0.05). CONCLUSION: The present study's findings indicate that participants with a body composition of ~20% body fat displayed the highest level of physical function at baseline. Furthermore, despite small pre-post changes in body fat, the results indicate that those who either preserved their body fat percentage or experienced minor alterations observed the greatest improvements in physical function.


Asunto(s)
Composición Corporal , Fuerza Muscular , Masculino , Humanos , Anciano , Estudios Transversales , Tejido Adiposo
18.
J Comp Neurol ; 531(17): 1772-1795, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37782702

RESUMEN

Accurate anatomical characterizations are necessary to investigate neural circuitry on a fine scale, but for the rodent claustrum complex (CLCX), this has yet to be fully accomplished. The CLCX is generally considered to comprise two major subdivisions, the claustrum (CL) and the dorsal endopiriform nucleus (DEn), but regional boundaries to these areas are debated. To address this, we conducted a multifaceted analysis of fiber- and cytoarchitecture, genetic marker expression, and connectivity using mice of both sexes, to create a comprehensive guide for identifying and delineating borders to CLCX, including an online reference atlas. Our data indicated four distinct subregions within CLCX, subdividing both CL and DEn into two. Additionally, we conducted brain-wide tracing of inputs to CLCX using a transgenic mouse line. Immunohistochemical staining against myelin basic protein (MBP), parvalbumin (PV), and calbindin (CB) revealed intricate fiber-architectural patterns enabling precise delineations of CLCX and its subregions. Myelinated fibers were abundant dorsally in CL but absent ventrally, whereas PV expressing fibers occupied the entire CL. CB staining revealed a central gap within CL, also visible anterior to the striatum. The Nr2f2, Npsr1, and Cplx3 genes expressed specifically within different subregions of the CLCX, and Rprm helped delineate the CL-insular border. Furthermore, cells in CL projecting to the retrosplenial cortex were located within the myelin sparse area. By combining own experimental data with digitally available datasets of gene expression and input connectivity, we could demonstrate that the proposed delineation scheme allows anchoring of datasets from different origins to a common reference framework.


Mice are a highly tractable model for studying the claustrum complex (CLCX). However, without a consensus on how to delineate the CLCX in rodents, comparing results between studies is challenging. It is therefore important to expand our anatomical knowledge of the CLCX, to match the level of detail needed to study its functional properties. To improve and expand upon preexisting delineation schemes, we used the combinatorial expression of several markers to create a comprehensive guide to delineate the CLCX and its subregions, including an online reference atlas. This anatomical framework will allow researchers to anchor future experimental data into a common reference space. We demonstrated the power of this new structural framework by combining our own experimental data with digitally available data on gene expression and input connectivity of the CLCX.


Asunto(s)
Claustro , Masculino , Femenino , Ratones , Animales , Claustro/metabolismo , Calbindinas/metabolismo , Encéfalo/metabolismo , Parvalbúminas/metabolismo , Roedores/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Proteínas Adaptadoras Transductoras de Señales
19.
United European Gastroenterol J ; 11(6): 551-563, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37300377

RESUMEN

BACKGROUND: The role of radiological staging and surveillance imaging is under debate for T1 colorectal cancer (CRC) as the risk of distant metastases is low and imaging may lead to the detection of incidental findings. OBJECTIVE: The aim of this study was to evaluate the yield of radiological staging and surveillance imaging for T1 CRC. METHODS: In this retrospective multicenter cohort study, all patients of 10 Dutch hospitals with histologically proven T1 CRC who underwent radiological staging in the period 2000-2014 were included. Clinical characteristics, pathological, endoscopic, surgical and imaging reports at baseline and during follow-up were recorded and analyzed. Patients were classified as high-risk T1 CRC if at least one of the histological risk factors (lymphovascular invasion, poor tumor differentiation, deep submucosal invasion or positive resection margins) was present and as low-risk when all risk factors were absent. RESULTS: Of the 628 included patients, 3 (0.5%) had synchronous distant metastases, 13 (2.1%) malignant incidental findings and 129 (20.5%) benign incidental findings at baseline staging. Radiological surveillance was performed among 336 (53.5%) patients. The 5-year cumulative incidence of distant recurrence, malignant and benign incidental findings were 2.4% (95% confidence interval (CI): 1.1%-5.4%), 2.5% (95% CI: 0.6%-10.4%) and 18.3% (95% CI: 13.4%-24.7%), respectively. No distant metastatic events occurred among low-risk T1 CRC patients. CONCLUSION: The risk of synchronous distant metastases and distant recurrence in T1 CRC is low, while there is a substantial risk of detecting incidental findings. Radiological staging seems unnecessary prior to local excision of suspected T1 CRC and after local excision of low-risk T1 CRC. Radiological surveillance should not be performed in patients with low-risk T1 CRC.


Asunto(s)
Neoplasias Colorrectales , Humanos , Estudios de Cohortes , Factores de Riesgo , Radiografía , Neoplasias Colorrectales/diagnóstico por imagen , Neoplasias Colorrectales/epidemiología
20.
Carbohydr Polym ; 276: 118804, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34823810

RESUMEN

This work explores the largely unknown surface microstructure and elastic modulus of soft calcium-alginate hydrogels (E = 100-4500 Pa) in their hydrated state by atomic force microscopy (AFM) in quantitative imaging mode. Alginate concentration influenced the surface topography with surface roughness measured to be 101 ± 6 nm and 57 ± 1 nm for 0.5 and 2.0% (w/v) alginate, respectively. The calculated range of pore sizes increased with decreasing alginate concentration, with radii smaller than 360 nm, 570 nm and 1230 nm for 2.0%, 1.0% and 0.5% alginate, respectively. Small changes in calcium concentration (from 20 to 25 mM, 1.5% alginate) did not induce changes in surface microstructure, although it increased the elastic modulus mean values and distribution. Introducing oxidized or peptide-grafted alginate in the gels resulted in rougher surfaces, larger pore sizes and lower elasticity than the respective hydrogels with no modified alginate.

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