189 research outputs found
Are Long Term Cryopreservation and Patency of Vein Allograft Truly Achievable?
Despite extensive experimental work, neither the effect of long term cryopreservation on vein graft architecture nor the failure of alloveins due to graft rejection have yet been investigated. Herein, we investigated ultrastructurally: a) the integrity of rabbit jugular veins following 1, 2 and 3 months of cryopreservation; b) the outcome of the three-month cryopreserved vein auto- and allografts after 1 month of implantation in the rabbit carotid artery; and c) the immunologic response to cryopreserved vein allografts with and without seeded autologous endothelium. Prior to implantation, the cryopreserved rabbit veins were well-maintained except for endothelial cell damage. Following implantation, the cryopreserved vein autografts were comparable to fresh veins with a complete endothelial lining. Conversely, only one of the allograft was still patent with features of acute rejection. After seeding with autologous endothelium , these explants failed shortly after surgery. We found absence of endothelium and necrosis of the media components with neutrophil infiltration. Although three months of cryopreservation does not affect vein graft architecture significantly, endothelial cells are damaged irrespective of the time of cryopreservation. Vein autografts promptly healed after one month of implantation at which time a viable endothelial cell lining was restored from the host artery. Conversely, vein allografts, with and without seeded autologous endothelium, failed due to graft rejection. This study highlights that current methods of cryopreservation do not reduce antigenicity of venous allografts significantly
Thalamocortical connectivity in experimentally-induced migraine attacks: A pilot study
In this study we used nitroglycerin (NTG)-induced migraine attacks as a translational human disease model. Static and dynamic functional connectivity (FC) analyses were applied to study the associated functional brain changes. A spontaneous migraine-like attack was induced in five episodic migraine (EM) patients using a NTG challenge. Four task-free functional magnetic resonance imaging (fMRI) scans were acquired over the study: baseline, prodromal, full-blown, and recovery. Seed-based correlation analysis (SCA) was applied to fMRI data to assess static FC changes between the thalamus and the rest of the brain. Wavelet coherence analysis (WCA) was applied to test time-varying phase-coherence changes between the thalamus and salience networks (SNs). SCA results showed significantly FC changes between the right thalamus and areas involved in the pain circuits (insula, pons, cerebellum) during the prodromal phase, reaching its maximal alteration during the full-blown phase. WCA showed instead a loss of synchronisation between thalami and SN, mainly occurring during the prodrome and full-blown phases. These findings further support the idea that a temporal change in thalamic function occurs over the experimentally induced phases of NTG-induced headache in migraine patients. Correlation of FC changes with true clinical phases in spontaneous migraine would validate the utility of this model
Human brain harbors single nucleotide somatic variations in functionally relevant genes possibly mediated by oxidative stress
Somatic variation in DNA can cause cells to deviate from the preordained
genomic path in both disease and healthy conditions. Here, using exome
sequencing of paired tissue samples, we show that the normal human brain
harbors somatic single base variations measuring up to 0.48% of the total
variations. Interestingly, about 64% of these somatic variations in the brain are
expected to lead to non-synonymous changes, and as much as 87% of these
represent G:C>T:A transversion events. Further, the transversion events in the
brain were mostly found in the frontal cortex, whereas the corpus callosum from
the same individuals harbors the reference genotype. We found a significantly
higher amount of 8-OHdG (oxidative stress marker) in the frontal cortex
compared to the corpus callosum of the same subjects (p<0.01), correlating
with the higher G:C>T:A transversions in the cortex. We found significant
enrichment for axon guidance and related pathways for genes harbouring
somatic variations. This could represent either a directed selection of genetic
variations in these pathways or increased susceptibility of some loci towards
oxidative stress. This study highlights that oxidative stress possibly influence
single nucleotide somatic variations in normal human brain
Efecto de las propiedades físicas, químicas, biológicas del suelo bajo siembra directa y trasplante en combinación con abonos verdes antecesores, sobre la producción de hortalizas en sistemas agroecológicos
Durante los años 2007-2012 fueron analizados dos tratamientos de sistemas de implantación de cultivos hortícolas; uno siembra directa de semillas (SD) y otro transplante de plantines (TR). Estos se combinaron con cuatro antecesores de manejo de suelos. Los tratamientos antecesores fueron: (H1) barbecho desnudo estival antes del policultivo de lechuga, acelga, remolacha, (H2) moha antes del policultivo de lechuga, acelga, remolacha, (H3) sorgo forrajero antes del cultivo de cebolla de verdeo, (H4) avena antes del cultivo de zapallo. El experimento tuvo diseño factorial con dos sistema de implantación, cuatro antecesores y tres repeticiones. En el período 2007-2009 fueron analizadas las variables, físicas, químicas, biológicas de la matriz del suelo: densidad aparente (DAP), infiltración básica (IB), porosidad total (PT), distribución de macroporos (MP), mesoporos (MSP), microporos (MCP), estabilidad de agregados (IEA), pH, conductividad eléctrica (CE), sulfatos (SO4), carbono orgánico total (COT), nitrógeno total (NT), fósforo extractable (Pe), calcio (Ca), magnesio (Mg), potasio (K), sodio (Na), capacidad de intercambio catiónico (CIC), respiración (AB), carbono en la biomasa microbiana (CBM), coeficientes metabólicos (qCO2), fluoresceína difosfato (FDA) y fosfatasa ácida (Pasa). También fueron registrados los rendimientos de las hortalizas luego de los antecesores. El análisis estadístico de todas las variables se realizó mediante dos procedimientos, modelos lineales (ANOVA, STEPWISE) y componentes principales (ACP). Existieron interacciones significativas entre sistema de implantación SD y TR y antecesores H1, H2, H3, H4, pero no fueron tan acentuadas, como la separación de tratamientos de SD y TR mediante ACP, lo que explicó el 83,4% de la variación ocurrida. Las variables biológicas y la IB explicaron en mayor medida los resultados obtenidos al favor del TR en los rendimientos de lechuga y acelga. Por el contrario las variables químicas y el IEA explicaron en mayor medida los resultados obtenidos a favor de la SD en el rendimiento de remolacha.EEA San PedroFil: Ullé, Jorge Angel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; ArgentinaFil: Faggioli, Valeria Soledad. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juarez; ArgentinaFil: Serri, Dannae Lilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Ortega y Villasana, Pilar. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Investigación y Desarrollo Tecnológico para la Agricultura Familiar Región NEA; ArgentinaFil: Darder, María Liliana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Dalpiaz, María Jimena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: García, Leticia Soledad. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Farroni, Abel Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Rimatori, Fernando Miguel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Colombini, F. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Villalba, D. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; Argentin
Indicadores de calidad edáfica en cultivos antecesores consociados y monocultivo de batata
Un experimento con batata cv Arapey, fue implantado en 2011 en Argiudoles evaluando diferentes tipos de manejo de suelos. Fueron comparados los manejos de mayor adopción como monocultivo y antecesor barbecho desnudo, con otras prácticas de manejo conservacionistas como antecesores de variedades de maíz (cv. Blanco Duro, cv. Caiano, cv Azteca), sorgo forrajero (cv. Talero), leguminosas subtropicales (Canavalia ensiformis, Mucuna cinza) y cultivo de batata (cv Arapey) de forma consociada en hileras con estos (cv Blanco Duro, Cv Caiano, Canavalia ensiformis). Fueron implementados 12 tratamientos y tres repeticiones, en diseño en bloques aleatorizados (DBCA) en un ensayo con objetivo de larga duración en la EEA San Pedro. Las batatas fueron trasplantadas, en 2011, 2012, 2013, siendo aquí comunicados los resultados de las primeras dos cosechas. En el primer año se cosecharon y registraron los rendimientos (ha) de los tratamientos de batata monocultivo, batata consociada con variedades maíz (cv Blanco Duro, cv. Caiano) y batata con leguminosas (Canavalia ensiformis). En el segundo año se cosecharon los tratamientos luego de los antecesores, barbecho desnudo, maíz (cv. Blanco Duro, cv. Caiano, cv Azteca), sorgo (cv. Talero) y leguminosas (Canavalia ensiformis). En cada situación fueron levantadas para la determinación las variables edáficas, físicas, químicas, biológicas: densidad aparente (DAP), infiltración básica (IB), porosidad total (PT), distribución de macroporos (MP), mesoporos (MSP), microporos (MCP), estabilidad de agregados (EA), pH, conductividad eléctrica (CE), carbono orgánico total (COT), nitrógeno total (NT), fósforo extractable (Pe), calcio (Ca), magnesio (Mg), potasio (K), sodio (Na), capacidad de intercambio catiónico (CIC), respiración (AB), carbono en la biomasa microbiana (CBM), coeficientes metabólicos (qCO2), fluoresceína difosfato (FDA) , fosfatasa ácida (Pasa), glomalinas (PROT) e hifas (H) arbúsculos (A) y vesículas (V) de micorrizas. El objetivo del trabajo fue conocer en qué medida el conjunto de variables-indicadores, permitían diferenciar las situaciones de manejo. En el análisis ANOVA, en el primer año 2012 los rendimientos de batata no difirieron significativamente, mientras que en el segundo 2013, la batata monocultivo, el antecesor barbecho desnudo, sorgo (cv. Talero) y leguminosa (Canavalia ensiformis), superaron significativamente a las batatas consociadas en hileras con variedades de maíz (cv Blanco Duro, Cv Caiano) y Canavalia ensiformis. El análisis de regresión múltiple (stepwise) en el primer año 2012, demostró un alta relación del rendimiento de batata con las variables biológicas, (CBM), (PROT), (qCO2) (R²= 0.65) y las físicas (MP), (MCP) (R²= 0.66). En el segundo año 2013, los rendimientos de batata presentaron una baja relación en sentido negativa con las variables biológicas (FDA) (Pasa), (PROT) (R²= 0.40), y las físicas (EA) (MSP) (R²= 0.26), pero una alta relación positiva con el Nt (R²= 0.85). El análisis de componentes principales separó mediante el CP1 (38,7% de la variación ocurrida), los tratamientos consociados del monocultivo, demostrando los consociados agruparse en un cuadrante junto a los rendimientos de batata 2012, la (FDA), (Pasa), (PROT), (MCP), (EA). Por el contrario, los de monocultivo se agruparon junto a los rendimientos de batata 2013, las variables químicas en su totalidad, las físicas (MP), (MSP) y micorrizas (H), (A), (V) en otro extremo.EEA San PedroFil: Ullé, Jorge Angel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; ArgentinaFil: Marti, Héctor Rubén.Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; ArgentinaFil: Faggioli, Valeria Soledad. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juarez; ArgentinaFil: Darder, María Liliana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Dalpiaz, María Jimena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Farroni, Abel Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Rimatori Fernando Miguel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Colombini, F. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Villalba, D. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Martinez, Fortunato. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Investigación y Desarrollo Tecnológico para la Agricultura Familiar Región NEA; ArgentinaFil: Ortega y Villasana, Pilar. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Investigación y Desarrollo Tecnológico para la Agricultura Familiar Región NEA; Argentin
Optimal management of asymptomatic carotid stenosis in 2021: the jury is still out. An International, multispecialty, expert review and position statement
Objectives: The recommendations of international guidelines for the management of asymptomatic carotid stenosis (ACS) often vary considerably and extend from a conservative approach with risk factor modification and best medical treatment (BMT) alone, to a more aggressive approach with a carotid intervention plus BMT. The aim of the current multispecialty position statement is to reconcile the conflicting views on the topic. Materials and methods: A literature review was performed with a focus on data from recent studies. Results: Several clinical and imaging high-risk features have been identified that are associated with an increased long-term ipsilateral ischemic stroke risk in patients with ACS. Such high-risk clinical/imaging features include intraplaque hemorrhage, impaired cerebrovascular reserve, carotid plaque echolucency/ulceration/ neovascularization, a lipid-rich necrotic core, a thin or ruptured fibrous cap, silent brain infarction, a contralateral transient ischemic attack/stroke episode, male patients <75 years and microembolic signals on transcranial Doppler. There is growing evidence that 80-99% ACS indicate a higher stroke risk than 50-79% stenoses. Conclusions: Although aggressive risk factor control and BMT should be implemented in all ACS patients, several high-risk features that may increase the risk of a future cerebrovascular event are now documented. Consequently, some guidelines recommend a prophylactic carotid intervention in high-risk patients to prevent future cerebrovascular events. Until the results of the much-anticipated randomized controlled trials emerge, the jury is still out regarding the optimal management of ACS patients
Optimal Management of Asymptomatic Carotid Stenosis in 2021:The Jury is Still Out. An International, Multispecialty, Expert Review and Position Statement
Objectives: The recommendations of international guidelines for the management of asymptomatic carotid stenosis (ACS) often vary considerably and extend from a conservative approach with risk factor modification and best medical treatment (BMT) alone, to a more aggressive approach with a carotid intervention plus BMT. The aim of the current multispecialty position statement is to reconcile the conflicting views on the topic.
Materials and methods: A literature review was performed with a focus on data from recent studies.
Results: Several clinical and imaging high-risk features have been identified that are associated with an increased long-term ipsilateral ischemic stroke risk in patients with ACS. Such high-risk clinical/imaging features include intraplaque hemorrhage, impaired cerebrovascular reserve, carotid plaque echolucency/ulceration/ neovascularization, a lipid-rich necrotic core, a thin or ruptured fibrous cap, silent brain infarction, a contralateral transient ischemic attack/stroke episode, male patients < 75 years and microembolic signals on transcranial Doppler. There is growing evidence that 80–99% ACS indicate a higher stroke risk than 50–79% stenoses.
Conclusions: Although aggressive risk factor control and BMT should be implemented in all ACS patients, several high-risk features that may increase the risk of a future cerebrovascular event are now documented. Consequently, some guidelines recommend a prophylactic carotid intervention in high-risk patients to prevent future cerebrovascular events. Until the results of the much-anticipated randomized controlled trials emerge, the jury is still out regarding the optimal management of ACS patients
Comparison of single- and multistage strategies during fenestrated-branched endovascular aortic repair of thoracoabdominal aortic aneurysms
Objective: The aim of this study was to compare outcomes of single or multistage approach during fenestrated-branched endovascular aortic repair (FB-EVAR) of extensive thoracoabdominal aortic aneurysms (TAAAs). Methods: We reviewed the clinical data of consecutive patients treated by FB-EVAR for extent I to III TAAAs in 24 centers (2006-2021). All patients received a single brand manufactured patient-specific or off-the-shelf fenestrated-branched stent grafts. Staging strategies included proximal thoracic aortic repair, minimally invasive segmental artery coil embolization, temporary aneurysm sac perfusion and combinations of these techniques. Endpoints were analyzed for elective repair in patients who had a single- or multistage approach before and after propensity score adjustment for baseline differences, including the composite 30-day/in-hospital mortality and/or permanent paraplegia, major adverse event, patient survival, and freedom from aortic-related mortality. Results: A total of 1947 patients (65% male; mean age, 71 ± 8 years) underwent FB-EVAR of 155 extent I (10%), 729 extent II (46%), and 713 extent III TAAAs (44%). A single-stage approach was used in 939 patients (48%) and a multistage approach in 1008 patients (52%). A multistage approach was more frequently used in patients undergoing elective compared with non-elective repair (55% vs 35%; P < .001). Staging strategies were proximal thoracic aortic repair in 743 patients (74%), temporary aneurysm sac perfusion in 128 (13%), minimally invasive segmental artery coil embolization in 10 (1%), and combinations in 127 (12%). Among patients undergoing elective repair (n = 1597), the composite endpoint of 30-day/in-hospital mortality and/or permanent paraplegia rate occurred in 14% of single-stage and 6% of multistage approach patients (P < .001). After adjustment with a propensity score, multistage approach was associated with lower rates of 30-day/in-hospital mortality and/or permanent paraplegia (odds ratio, 0.466; 95% confidence interval, 0.271-0.801; P = .006) and higher patient survival at 1 year (86.9±1.3% vs 79.6±1.7%) and 3 years (72.7±2.1% vs 64.2±2.3%; adjusted hazard ratio, 0.714; 95% confidence interval, 0.528-0.966; P = .029), compared with a single stage approach. Conclusions: Staging elective FB-EVAR of extent I to III TAAAs was associated with decreased risk of mortality and/or permanent paraplegia at 30 days or within hospital stay, and with higher patient survival at 1 and 3 years
Differential baseline and response profile to IFN-γ gene transduction of IL-6/IL-6 receptor-α secretion discriminate primary tumors versus bone marrow metastases of nasopharyngeal carcinomas in culture
<p>Abstract</p> <p>Background</p> <p>Understanding of immunobiology of bone marrow metastases (designated BM-NPC) <it>versus </it>primary tumors (P-NPC) of the nasopharynx is far from complete. The aim of this study was to determine if there would be differences between cultured P-NPCs and BM-NPCs with respect to (i) constitutive IL-6 and the IL-6 receptor gp80 subunit (IL-6Rα) levels in the spent media of nontransduced cells, and (ii) IL-6 and IL-6Rα levels in the spent media of cells transduced with a retroviral vector containing the <it>IFN-γ </it>gene.</p> <p>Methods</p> <p>A panel of NPC cell lines were transduced with the <it>IFN-γ </it>gene through a retroviral vector. Four clonal sublines were isolated <it>via </it>limiting dilution methods. Cytofluorometric analysis was performed for the detection of cell surface antigens of HLA class I, HLA class II and ICAM-1. ELISA was used to assay for IFN-γ, IL-6 and IL-6Rα in the spent media of cultured cell lines.</p> <p>Results</p> <p>Our results showed that in day 3 culture supernatants, low levels of soluble IL-6 were detected in 5/5 cultured tumors derived from P-NPCs, while much higher constitutive levels of IL-6 were detected in 3/3 metastasis-derived NPC cell lines including one originated from ascites; the difference was significant (<it>p </it>= 0.025). An inverse relationship was found between IL-6Rα and IL-6 in their release levels in cultured P-NPCs and metastasis-derived NPCs. In <it>IFN-γ</it>-transduced-P-NPCs, IL-6 production increased and yet IL-6Rα decreased substantially, as compared to nontransduced counterparts. At variance with P-NPC cells, the respective ongoing IL-6 and IL-6Rα release patterns of BM-NPC cells were not impeded as much following <it>IFN-γ </it>transduction. These observations were confirmed by extended kinetic studies with representative NPC cell lines and clonal sublines. The latter observation with the clonal sublines also indicates that selection for high IL-6 or low IL-6Rα producing subpopulations did not occur as a result of <it>IFN-γ</it>-transduction process. P-NPCs, which secreted constitutively only marginal levels of IFN-γ (8.4 ~ 10.5 pg/ml), could be enhanced to produce higher levels of IFN-γ (6.8- to 10.3-fold increase) after <it>IFN-γ </it>transduction. Unlike P-NPCs, BM-NPCs spontaneously released IFN-γ at moderate levels (83.8 ~ 100.7 pg/ml), which were enhanced by 1.3- to 2.2-fold in the spent media of their <it>IFN-γ</it>-transduced counterparts.</p> <p>Conclusion</p> <p>Our results showed that cultured P-NPCs and BM-NPCs could be distinguished from one another on the basis of their differential baseline secretion pattern of IFN-γ, IL-6 and IL-6Rα, and their differential response profiles to <it>IFN-γ </it>gene transfer of the production of these three soluble molecules. These results suggest that the IL-6 and IFN-γ pathways in a background of genetic instability be involved in the acquisition of metastatic behaviour in BM-NPCs.</p
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