Medical imaging: Foundations and scope

Indexación: Scopus; Radalyc.En la actualidad es innegable la utilidad de las diversas modalidades de imagenología médica como apoyo clínico tanto en la generación de diagnósticos de un buen número de enfermedades como en la planeación de tratamientos tendientes a proporcionar una alternativa de solución a las personas que, por una u otra razón, manifiestan algún desequilibrio en su salud. Entre las modalidades imagenológicas que, frecuentemente, se utilizan en el ámbito médico se pueden mencionar: Ultrasonido (US), Resonancia Magnética (MRI), Tomografía Computarizada sencilla (CT) y multicapa (MSCT), Tomografía Computarizada por Emisión de Positrones (PET) y Tomografía Computarizada por Emisión de Fotones simples (SPECT). En este sentido, este artículo tiene como finalidad presentar una descripción ordenada, coherente y sistemática de cada una de las mencionadas modalidades y establecer la vinculación de la MSCT con situaciones clínicas íntimamente relacionadas con la anatomía cardiaca y procesos de hipertensión. La razón por la cual se hace énfasis en la MSCT es debido a que, por una parte, se cuenta con un número importante de bases de datos tanto de sujetos fisiológicos como de sujetos patológicos y, por la otra, que se tiene previsto presentar un conjunto de técnicas computacionales que serán exploradas en el desarrollo de futuras investigaciones en el contexto de aspectos anatómico-cardiológicos que influyen directa o indirectamente en la aparición, desarrollo y prevalencia de procesos hipertensivos.Nowdays, several forms of medical imaging are usefulness in clinical support for both diagnostics diseases generation and treatment planning designed to provide an alternative solution to people who, for one or another reason, manifest an imbalance in your health. Among the imaging modalities that frequently are used in the medical field may include: Ultrasound (US), magnetic resonance imaging (MRI), simple computed tomography (CT) and multilayer computed tomography (MSCT), CT positron emission tomography (PET) Computed tomography and single photon emission (SPECT). In this sense, this article presents an orderly, coherent and systematic description of these modalities and it establishes relationship with the MSCT modality and clinical situations closely related to cardiac anatomy and hypertension processes. The reason emphasis on MSCT is done is because, on the one hand, we have a large number of databases both physiological subjects and pathological subjects and, on the other, we plan to present a set of computational techniques that will be explored in future research, in the context of cardiologic anatomical aspects, with directly or indirectly influence in the emergence, development and prevalence of hypertensive processes.http://www.redalyc.org/articulo.oa?id=5594990700

Ciclo biológico y exploración de parasitismo en Specularius impressithorax (Pic) 1932 (Coleoptera: Bruchidae) en México

El brúquido Specularius impressithorax es un insecto deorigen africano cuyo desplazamiento se ha dado de manera importante a nivel mundial debido a que se le ha encontrado en países como la India, Estados Unidos (Hawaii, California) y actualmente México, en este último desplazándose a varios estados de la República, en gran parte debido a que su principal fuente de alimento son las semillas de plantas del género Erythrina, las cuales se encuentran abundantemente en zonas con climas desde semiáridos hasta secos o templados; el clima en México y la diversidad de especies de Erythrina ha favorecido al establecimiento del insecto y por lo tanto el ataque a nuevos hospederos. Para el estudio del ciclo biológico del insecto se realizó la cría del mismo y se cuantificó el número de huevos depositados y el tiempo requerido para cada etapa de desarrollo, todo ello a temperatura ambiente (18 - 22 °C) y temperatura controlada de 25 ºC ± 2 ºC; tambiénse observó la polifagia hacia nuevos hospederos y la exploraciónde parasitismo en S. impressithorax. Los resultados mostraron que S.impressithorax en condiciones controladas de laboratorio presenta una disminución en la oviposición de huevos viables, en comparación con la temperatura ambiente, en donde la mayoría de los huevos llegaron a ser fértiles y la población llegó a estado adulto. Insectos vírgenes de S.impressithorax fueron colocados en contenedores donde se les agregó alimento de diferentes especies de Erythrina originarias de México y se evaluó la preferencia alimenticia. Se observó que fue capaz de invadir nuevos hospederos y de ellos emergieron adultos. Al realizar las colectas en donde se presentaban semillas de eritrinas infestadas por S. impressithorax se observó la presencia de parasitoides de huevos, éstos se identificaron como Uscana sp. (Hymenoptera: Trichogrammatidae); sin embargo, no se han podido obtener formas adultas libres para la corroboración de la especie; el segundo enemigo natural encontrado correspondió a Entedeon erythrinae Gumovsky y Ramadan (Hymenoptera:Eulophidae), se trata de un parasitoide de huevo-larva del brúquido. Los datos anteriores indican que la infestación hacia nuevos hospederos de eritrinas y el incremento de su dispersión será inminente y que hace falta realizar estrategias de control del brúquido; el control biológico se puede incluir en su manejo y así evitar el deterioro del germoplasma de los hospederos, mismos que realizan funciones importantes en la ecología, la etnobótanica y la ciencia

A hypoperfusion context may aid to interpret hyperlactatemia in sepsis-3 septic shock patients: a proof-of-concept study

__Background:__ Persistent hyperlactatemia is particularly difficult to interpret in septic shock. Besides hypoperfusion, adrenergic-driven lactate production and impaired lactate clearance are important contributors. However, clinical recognition of different sources of hyperlactatemia is unfortunately not a common practice and patients are treated with the same strategy despite the risk of over-resuscitation in some. Indeed, pursuing additional resuscitation in non-hypoperfusion-related cases might lead to the toxicity of fluid overload and vasoactive drugs. We hypothesized that two different clinical patterns can be recognized in septic shock patients through a multimodal perfusion monitoring. Hyperlactatemic patients with a hypoperfusion context probably represent a more severe acute circulatory dysfunction, and the absence of a hypoperfusion context is eventually associated with a good outcome. We performed a retrospective analysis of a database of septic shock patients with persistent hyperlactatemia after initial resuscitation. __Results:__ We defined hypoperfusion context by the presence of a ScvO2 < 70%, or a P(cv-a)CO2 ≥6 mmHg, or a CRT ≥4 s together with hyperlactatemia. Ninety patients were included, of whom seventy exhibited a hypoperfusion-related pattern and 20 did not. Although lactate values were comparable at baseline (4.8 ± 2.8 vs. 4.7 ± 3.7 mmol/L), patients with a hypoperfusion context exhibited a more severe circulatory dysfunction with higher vasopressor requirements, and a trend to longer mechanical ventilation days, ICU stay, and more rescue therapies. Only one of the 20 hyperlactatemic patients without a hypoperfusion context died (5%) compared to 11 of the 70 with hypoperfusion-related hyperlactatemia (16%). __Conclusions:__ Two different clinical patterns among hyperlactatemic septic shock patients may be identified according to hypoperfusion context. Patients with hyperlactatemia plus low ScvO2, or high P(cv-a)CO2, or high CRT values exhibited a more severe circulatory dysfunction. This provides a starting point to launch further prospective studies to confirm if this approach can lead to a more selective resuscitation strategy

Effects of capillary refill time-vs. lactate-targeted fluid resuscitation on regional, microcirculatory and hypoxia-related perfusion parameters in septic shock: a randomized controlled trial

Background: Persistent hyperlactatemia has been considered as a signal of tissue hypoperfusion in septic shock patients, but multiple non-hypoperfusion-related pathogenic mechanisms could be involved. Therefore, pursuing lactate normalization may lead to the risk of fuid overload. Peripheral perfusion, assessed by the capillary refll time (CRT), could be an efective alternative resuscitation target as recently demonstrated by the ANDROMEDA-SHOCK trial. We designed the present randomized controlled trial to address the impact of a CRT-targeted (CRT-T) vs. a lactate-targeted (LAC-T) fuid resuscitation strategy on fuid balances within 24 h of septic shock diagnosis. In addi‑ tion, we compared the efects of both strategies on organ dysfunction, regional and microcirculatory fow, and tissue hypoxia surrogates. Results: Forty-two fuid-responsive septic shock patients were randomized into CRT-T or LAC-T groups. Fluids were administered until target achievement during the 6 h intervention period, or until safety criteria were met. CRT-T was aimed at CRT normalization (≤3 s), whereas in LAC-T the goal was lactate normalization (≤2 mmol/L) or a 20% decrease every 2 h. Multimodal perfusion monitoring included sublingual microcirculatory assessment; plasma-disap‑ pearance rate of indocyanine green; muscle oxygen saturation; central venous-arterial pCO2 gradient/ arterial-venous O2 content diference ratio; and lactate/pyruvate ratio. There was no diference between CRT-T vs. LAC-T in 6 h-fuid boluses (875 [375–2625] vs. 1500 [1000–2000], p=0.3), or balances (982[249–2833] vs. 15,800 [740–6587, p=0.2]). CRT-T was associated with a higher achievement of the predefned perfusion target (62 vs. 24, p=0.03). No signifcant diferences in perfusion-related variables or hypoxia surrogates were observed. Conclusions: CRT-targeted fuid resuscitation was not superior to a lactate-targeted one on fuid administration or balances. However, it was associated with comparable efects on regional and microcirculatory fow parameters and hypoxia surrogates, and a faster achievement of the predefned resuscitation target. Our data suggest that stopping fuids in patients with CRT≤3 s appears as safe in terms of tissue perfusion

Forests as Commons – Changing Traditions and Governance in Europe

Commons are complex institutions and exist across the world in a wide range of situations regarding locally developed governance and management systems of many different natural resources. For many people commons remain associated with Hardin’s theory concerning the “Tragedy of the Commons” (1968), in which he assumed that local users of a natural resource are unable to formulate governance and management structures concerning their own choices that took into account the long-term sustainability of the resource itself. As a result, Hardin articulated that the tragedy was that the resource would inevitably become degraded in such situations and that the solution was private or public ownership. However, across Europe many forests have for a very long period of time successfully been managed as commons, just as they have in many other parts of the world. This chapter has three main aims: It will provide an introduction to the various types of commons before going on to link the issue of commons to the traditional forest landscapes of Europe, and it will look at how the role of forests and forest landscapes has changed and how it may change further in the future

The 10 kDa domain of human erythrocyte protein 4.1 binds the Plasmodium falciparum EBA-181 protein

BACKGROUND: Erythrocyte invasion by Plasmodium falciparum parasites represents a key mechanism during malaria pathogenesis. Erythrocyte binding antigen-181 (EBA-181) is an important invasion protein, which mediates a unique host cell entry pathway. A novel interaction between EBA-181 and human erythrocyte membrane protein 4.1 (4.1R) was recently demonstrated using phage display technology. In the current study, recombinant proteins were utilized to define and characterize the precise molecular interaction between the two proteins. METHODS: 4.1R structural domains (30, 16, 10 and 22 kDa domain) and the 4.1R binding region in EBA-181 were synthesized in specific Escherichia coli strains as recombinant proteins and purified using magnetic bead technology. Recombinant proteins were subsequently used in blot-overlay and histidine pull-down assays to determine the binding domain in 4.1R. RESULTS: Blot overlay and histidine pull-down experiments revealed specific interaction between the 10 kDa domain of 4.1R and EBA-181. Binding was concentration dependent as well as saturable and was abolished by heat denaturation of 4.1R. CONCLUSION: The interaction of EBA-181 with the highly conserved 10 kDa domain of 4.1R provides new insight into the molecular mechanisms utilized by P. falciparum during erythrocyte entry. The results highlight the potential multifunctional role of malaria invasion proteins, which may contribute to the success of the pathogenic stage of the parasite's life cycle

Guide to the alien and invasive species of rivers, lakes and estuaries in the Iberian Peninsula.

Guide to the alien and invasive species of rivers, lakes and estuaries in the Iberian Peninsula

Engineering of Three-Finger Fold Toxins Creates Ligands with Original Pharmacological Profiles for Muscarinic and Adrenergic Receptors

Protein engineering approaches are often a combination of rational design and directed evolution using display technologies. Here, we test “loop grafting,” a rational design method, on three-finger fold proteins. These small reticulated proteins have exceptional affinity and specificity for their diverse molecular targets, display protease-resistance, and are highly stable and poorly immunogenic. The wealth of structural knowledge makes them good candidates for protein engineering of new functionality. Our goal is to enhance the efficacy of these mini-proteins by modifying their pharmacological properties in order to extend their use in imaging, diagnostics and therapeutic applications. Using the interaction of three-finger fold toxins with muscarinic and adrenergic receptors as a model, chimeric toxins have been engineered by substituting loops on toxin MT7 by those from toxin MT1. The pharmacological impact of these grafts was examined using binding experiments on muscarinic receptors M1 and M4 and on the α1A-adrenoceptor. Some of the designed chimeric proteins have impressive gain of function on certain receptor subtypes achieving an original selectivity profile with high affinity for muscarinic receptor M1 and α1A-adrenoceptor. Structure-function analysis supported by crystallographic data for MT1 and two chimeras permits a molecular based interpretation of these gains and details the merits of this protein engineering technique. The results obtained shed light on how loop permutation can be used to design new three-finger proteins with original pharmacological profiles