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BACKGROUND: Intracardiac echocardiography (ICE) has improved catheter ablation procedures, reducing reliance on fluoroscopy. Yet, the efficacy and safety of zero-fluoroscopy (ZF) procedures remain uncertain. METHODS: We conducted a systematic review and meta-analysis comparing ZF ablation procedures guided by ICE vs. conventional techniques regarding efficacy and safety outcomes. PubMed, Cochrane, and embase were searched. A random-effects model was used to calculate risk ratios (RRs), odds ratios (OR) and mean differences (MDs) with 95% confidence intervals (CI). RESULTS: We includedfourteen studies with 1,919 patients of whom 1,023 (58.72%) performed ZF ablation using ICE. We found a significant reduced ablation time (SMD -0.18; 95% CI -0.31;-0.04; p=0.009), procedure time (MD -7.54; 95% CI -14.68;-0.41; p=0.04), fluoroscopic time (MD -2.52; 95% CI -3.20;-1.84; p<0.001) in patients treated with ZF approach compared with NZF approach. However, there was no significant difference between the two groups in acute success rate (RR 1.00; 95% CI 0.99-1.01; p=0.85), long-term success rate (RR 0.99; 95% CI 0.93-1.05; p=0.77) and complications (RR 0.84, 95% CI: 0.48-1.46; p = 0.54). CONCLUSION: Our findings suggest that among patients undergoing arrhythmia ablation, fluoroscopy-free ICE-guided technique reduces procedure time and radiation exposure with comparable short and long-term success rates and complications.
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FluoroscopíaRESUMEN
BACKGROUND: Randomized studies support complete over culprit-only revascularization for patients with acute coronary syndrome (ACS) However,whether these findings extend to elderly patients has not been thoroughly explored. METHODS: We conducted a systematic review and meta-analysis comparing clinical outcomes of elderly individuals (defined as age > 75 years) with ACS and multivessel coronary artery disease submitted to complete vs. culprit-only percutaneous coronary intervention (PCI). PubMed, Embase, and Cochrane were searched. We computed pooled hazard ratios (HRs) with 95% confidence intervals (CI) to preserve time-to-event data RESULTS: We included 7 studies, of which 2 were randomized controlled trials (RCTs), comprising 7,409 patients, of whom 3225 (43.5%) underwent complete revascularization. As compared with culprit lesion only PCI, complete revascularization was associated with a lower risk of all-cause mortality (HR 0.76; 95% CI 0.68-0.85; p<0.001), cardiovascular mortality (HR 0.67; 95% CI 0.54-0.82; p<0.001), and recurrent myocardial infarction (MI) (HR 0.65; 95% CI 0.50-0.85; p=0.002). There was no significant difference between the groups regarding the risk of recurrent revascularizations (HR 0.79; 95% CI 0.54-1.16; p=0.23). CONCLUSION: Among elderly patients with ACS and multivessel CAD, complete revascularization is associated with a lower risk of all-cause mortality, cardiovascular mortality, and recurrent MI.
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Humanos , Anciano , Anciano de 80 o más Años , Angioplastia Coronaria con Balón , Síndrome Coronario Agudo , Revascularización MiocárdicaRESUMEN
BACKGROUND: Reflex syncope reduces quality of life and leads to fall-related injuries, with no highly effective treatment. In this context, cardioneuroablation (CNA) presents as a promising therapy for these patients. METHODS: We searched PubMed, Embase and Cochrane Central for studies that evaluated safety and efficacy outcomes related to CNA procedures. Two reviewers independently performed study selection, data extraction and assessment of bias. Generalized linear mixed models was used. We performed a single-arm meta-analysis using R version 4.2.3. RESULTS: A total of 25 studies comprising 871 patients were included. The mean follow-up ranged from 8 to 40 months. Mean age ranged from 32.9 to 53.9 years and 541 (62.1%) were female. The ablation target was biatrial in 302 patients (34%), left atrium only in 433 (49%), and right atrium only in 136 (15%). The freedom from syncope was 94% (95% confidence interval (CI) 90.13-97.00; P<0.01). Left and right atrial CNA was associated with a significant higher freedom from syncope (96.03%; 95% CI 93.13-97.73) than left atrial ablation only (94.61%; 95% CI 82.88-98.45) and right ablation only (84.53%; 95% CI 74.30-91.18). Peri-procedural adverse event occurred on 1.4% (95% CI 0.44- 4.50). CONCLUSION: Our findings suggest that in patients with reflex syncope, CNA is a procedure associated with a significant reduction in syncope incidence and with low complication rates. Among the procedures used, both right and left ablation were more effective.
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Ablación por CatéterRESUMEN
BACKGROUND: Selective cardiac myosin inhibitors (CMI) are promising therapies for obstructive hypertrophic cardiomyopathy (HCM). Yet, the extent of their benefits remains unclear due to the limited population studied. METHODS: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing CMI vs. placebo in patients with obstructive HCM. PubMed, Cochrane, and embase were searched. We calculated risk ratios (RRs), mean differences (MDs) and standardized mean differences (SMDs) with 95% confidence intervals (CI). RESULTS: Four RCTs with 485 patients with obstructive HCM were included, of whom 261 (53.8%) were prescribed CMI (10.7% were aficamten and 89.3% were mavacamten). CMI significantly reduced resting left ventricular outflow tract (LVOT) gradient (SMD -1.4, 95% CI -1.6,-1.2, p<0.001), but also reduced left ventricular ejection fraction (LVEF) (MD -5.1%, 95% CI -7.6,-2.6, p<0,001). Patients receiving CMI had a higher rate of study-defined complete hemodynamic response (RR 16.8, CI 95% 5.5, 51.4, p<0,001; Figure 1A) with a number needed to treat (NNT) of 8; and improvement of at least one point in NYHA functional class (RR 2.29, CI 95% 1.8,2.9, p<0,001; Figure 1B). Conclusion: In this meta-analysis of RCTs including patients with obstructive HCM, CMI led to a significant reduction in LVOT gradient and symptomatic improvement. The NNT to achieve one complete hemodynamic response was 8. There was a significant, albeit modest, decrease in LVEF in the CMI group.
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BACKGROUND: The use of anabolic androgenic steroids (AAS) among athletes has been linked to pathological structural and functional cardiac changes. However, the studies are small, and the results are inconsistent. METHODS: We conducted a systematic review and meta-analysis of echocardiographic outcomes comparing athletes with prolonged use of AAS (at least 2 years of use) versus sex and age- matched athletes who were did not use AAS. PubMed, Cochrane, and embase were searched. A random-effects model was used to calculate mean differences (MDs), with 95% confidence intervals (CI). Statistical analyses were performed using Review Manager 5.4.1. RESULTS: We included 17 studies comprising 1,023 athletes, of whom 543 (53%) were AAS users. The mean age ranged to 24.2 to 43 years. Compared with non-AAS users, athletes who used AAS exhibited a significant increase in interventricular septal wall thickness (MD 1.33 mm; 95% CI [0.8,1.89], p<0.001), a reduction in left ventricular ejection fraction (MD 2.77 %; 95% CI [-4.2,-1.34], p<0.001;Figure 1B) , and worsening of global longitudinal strain (MD 3.39%; 95% CI [2.88,3.91], p<0.001;Figure 1B). Additionally, there was a significant reduction in the E/A ratio (MD -0.21; 95% CI [-0.35,-0.07], p=0.003) and an increase in the E/e' ratio (MD 1.71; 95% CI [0.96,2.46], p<0.001). CONCLUSION: Our findings suggest that prolonged use of AAS in athletes is associated with increased left ventricular wall thickness and worsening of systolic and diastolic parameters.
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Disfunción Ventricular Izquierda , Atletas , Esteroides Anabólicos AndrogénicosRESUMEN
INTRODUCTION: Long-term data is limited on the comparative outcomes of percutaneous coronary intervention (PCI) with second-generation drug-eluting stents (S-DES) versus coronary artery bypass grafting (CABG) in patients with coronary artery disease (CAD). Hypothesis: Our aim was to conduct a systematic review and meta-analysis comparing mortality and cardiovascular outcomes in patients with left main or multivessel CAD who underwent PCI with an S-DES versus CABG with a minimum mean follow-up period of 3 years. METHODS: We searched PubMed, Embase, and Cochrane for studies that examined our clinical question. Three reviewers independently performed study selection and data extraction. Statistical analysis was performed using Review Manager 5.4.1. We calculated pooled hazard ratios (HR) with 95% confidence intervals (CI) under a random effects model. The data from observational studies were extracted and pooled as multivariable-adjusted HR or propensity score matching to minimize confounding. RESULTS: We included 10 studies, 2 of which were randomized controlled trials (RCT), with a total of 25,866 patients, of whom 11,482 (44.3%) underwent PCI. The mean follow-up ranged from 3.0 to 11.8 years. S-DES had a significantly higher risk than CABG for all-cause mortality (HR 1.36; 95% CI 1.10-1.68; p=0.005) and myocardial infarction (MI) (HR 1.89; 95% CI 1.12-3.18; p=0.02). No significant difference between the groups was found for major cardiovascular events (HR 1.10; 95% CI 0.98-1.23; p=0.11) and stroke (HR 0.83; CI: 0.60-1.15; p=0.27). In a subgroup analysis of RCTs, there was no significant difference between patients who underwent S-DES or CABG. CONCLUSION: In this meta-analysis of RCTs and multivariable or propensity-matched observational studies, our findings suggest that PCI with S-DES is associated with an increased risk of mortality and MI events compared with CABG in patients with left main or multivessel CAD.
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Background: The aim of the study was to describe the origin, course, and termination of frontal aslant tract (FAT) in the Mexican population of neurosurgical referral centers. Methods: From January 2018 to May 2019, we analyzed 50 magnetic resonance imaging (MRI) studies in diffusion tensor imaging sequences of patients of the National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez." Five brains were fixed by the Klingler method and dissected in the neurosurgery laboratory of the Hospital Civil de Guadalajara to identify the origin, trajectory, and ending of the FAT. Results: FAT was identified in 100% of the MRI and brain dissections. The origin of the FAT was observed in 63% from the supplementary premotor area, 24% from the supplementary motor area, and 13% in both areas. Its ending was observed in the pars opercularis in 81%, pars triangularis in 9%, and in both pars opercularis and ventral premotor area in 10% in the magnetic resonance images, with a left side predominance. In the hemispheres dissections, the origin of FAT was identified in 60% from the supplementary premotor area, 20% from the supplementary motor area, and 20% in both areas. Its ending was observed in the pars opercularis in 80% and the pars triangularis in 20%. It was not identified as an individual fascicle connected with the contralateral FAT. Conclusion: In the Mexican population, FAT has a left predominance; it is originated more frequently in the supplementary premotor area, passes dorsal to the superior longitudinal fascicle II and the superior periinsular sulcus, and ends more commonly in the pars opercularis.
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La actual pandemia por coronavirus afecta a pacientes de todas las edades y estratos socioeconómicos, los accidentes por quemaduras también. Las cirugías de urgencia y el manejo quirúrgico del gran quemado no pueden ser diferidos, por lo que en el presente artículo mostramos la experiencia y organización del Servicio de Quemados del Hospital de Urgencia de Asistencia Pública para manejar a los pacientes COVID-19 (+) y () que se encuentran actualmente en nuestra Unidad.
The current coronavirus pandemic affects patients of all ages and socio-economic strata, burn accidents as well. The emergency surgeries and the surgical management of the large burn cannot be delayed, so in this article we show the experience and organization of the Emergency Hospital Burn Service of Public Assistance to manage patients COVID-19 (+) and () who are currently in our Unit.
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Humanos , Quirófanos/normas , Medidas de Seguridad , Unidades de Quemados , Infecciones por Coronavirus/cirugíaRESUMEN
BACKGROUND: Expression and activity of the potassium channel ether-à-go-go-1 (EAG1) are strongly related to carcinogenesis and tumor progression, which can be exploited for therapeutic purposes. EAG1 activity may be reduced by preventing its phosphorylation with epidermal growth factor receptor (EGFR) kinase inhibitors and by astemizole, which blocks the channel pore and downregulates its gene expression. OBJECTIVE: We aimed to study the potential cooperative antiproliferative effect of the EGFR inhibitor gefitinib and the EAG1-blocker astemizole, in breast cancer cells. MATERIALS AND METHODS: The cells were characterized by immunocytochemistry. Inhibitory concentrations were determined by non-linear regression analysis using dose-response curves. The nature of the pharmacological effect was evaluated by the combination index equation while cell cycle analysis was studied by flow cy-tometry. RESULTS: Astemizole and gefitinib inhibited cell proliferation in a concentration-dependent manner, with inhibitory concentrations (IC 50) values of 1.72 µM and 0.51 µM, respectively. All combinations resulted in a synergistic antiproliferative effect. The combination of astemizole and gefitinib diminished the percentage of cells in G2/M and S phases, while increased accumulation in G0/G1 of the cell cycle. CONCLUSIONS: Astemizole and gefitinib synergistically inhibited proliferation in breast cancer cells expressing both EGFR and EAG1. Our results suggest that the combined treatment increased cell death by targeting the oncogenic activity of EAG1.
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Antineoplásicos/farmacología , Astemizol/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Gefitinib/farmacología , Antineoplásicos/administración & dosificación , Astemizol/administración & dosificación , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/genética , Canales de Potasio Éter-A-Go-Go/antagonistas & inhibidores , Canales de Potasio Éter-A-Go-Go/genética , Femenino , Gefitinib/administración & dosificación , Regulación Neoplásica de la Expresión Génica , Humanos , Concentración 50 Inhibidora , Inhibidores de Proteínas Quinasas/administración & dosificación , Inhibidores de Proteínas Quinasas/farmacologíaRESUMEN
Abstract Background Expression and activity of the potassium channel ether-à-go-go-1 (EAG1) are strongly related to carcinogenesis and tumor progression, which can be exploited for therapeutic purposes. EAG1 activity may be reduced by preventing its phosphorylation with epidermal growth factor receptor (EGFR) kinase inhibitors and by astemizole, which blocks the channel pore and downregulates its gene expression. Objective We aimed to study the potential cooperative antiproliferative effect of the EGFR inhibitor gefitinib and the EAG1-blocker astemizole, in breast cancer cells. Materials and Methods The cells were characterized by immunocytochemistry. Inhibitory concentrations were determined by non-linear regression analysis using dose-response curves. The nature of the pharmacological effect was evaluated by the combination index equation while cell cycle analysis was studied by flow cytometry. Results Astemizole and gefitinib inhibited cell proliferation in a concentration-dependent manner, with inhibitory concentrations (IC 50) values of 1.72 µM and 0.51 µM, respectively. All combinations resulted in a synergistic antiproliferative effect. The combination of astemizole and gefitinib diminished the percentage of cells in G2/M and S phases, while increased accumulation in G0/G1 of the cell cycle. Conclusions Astemizole and gefitinib synergistically inhibited proliferation in breast cancer cells expressing both EGFR and EAG1. Our results suggest that the combined treatment increased cell death by targeting the oncogenic activity of EAG1.
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Humanos , Femenino , Neoplasias de la Mama/tratamiento farmacológico , Astemizol/farmacología , Gefitinib/farmacología , Antineoplásicos/farmacología , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Regulación Neoplásica de la Expresión Génica , Astemizol/administración & dosificación , Concentración 50 Inhibidora , Línea Celular Tumoral , Inhibidores de Proteínas Quinasas/administración & dosificación , Inhibidores de Proteínas Quinasas/farmacología , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Canales de Potasio Éter-A-Go-Go/antagonistas & inhibidores , Canales de Potasio Éter-A-Go-Go/genética , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/genética , Gefitinib/administración & dosificación , Antineoplásicos/administración & dosificaciónRESUMEN
BACKGROUND: The celiac artery, celiac axis or celiac trunk is the first major abdominal branch of the aorta. Anatomic variations and accessory vessels have been reported with variable percentages. The purpose of this study was to report the pattern of the celiac trunk and its anatomic variations in a sample of Mexican population. METHODS: Celiac trunk dissection was performed in 140 fresh cadavers. Cadavers of Mexican subjects aged 18 years and older were included. Cadavers with previous upper abdominal surgery, abdominal trauma, disease process that distorted the arterial anatomy or signs of putrefaction were excluded. Celiac trunk variations and external diameter, accessory vessels, and vertebral level of origin were described. Celiac trunk patterns were reported according to the Panagouli classification. This study was reviewed and approved by the Ethics Committee of our Hospital. RESULTS: The celiac trunk derived in a common hepatic artery, a left gastric artery and a splenic artery (type I) in 43.6% of dissections. A true tripod was found in 7.1% and a false tripod in 36.4%. Celiac trunk bifurcation (type II) was found in 7.1%. Additional branches (type III) were observed in 47.9%. One or both phrenic arteries originated from the celiac trunk in 41.4% of dissections. Celiac trunk tetrafurcation was observed in 12.9%, pentafurcation in 12.9%, hexafurcation in 1.4%, and heptafurcation in 0.7%. The mean diameter of the celiac trunk ranged from 6 to 12 mm, with a mean diameter of 7.2 mm (SD = 1.39 mm). No significant difference was found between the diameters of the different types of celiac trunk (P > 0.05). The celiac trunk originated between the 12th thoracic and first lumbar vertebral bodies in 90% of dissections. CONCLUSIONS: Trifurcation of the celiac trunk was lower than previously reported. A high proportion of cases with additional vessels were found.
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BACKGROUND: The mammalian oocyte extracellular matrix known as the zona pellucida (ZP) acts as a barrier to accomplish sperm fusion with the female gamete. Although penetration of the ZP is a limiting event to achieve fertilization, this is one of the least comprehended stages of gamete interaction. Even though previous studies suggest that proteases of sperm origin contribute to facilitate the passage of sperm through the ZP, in human this process is not yet fully understood. The aim of this study was to determine the ability of human sperm to degrade recombinant human ZP (rhZPs) proteins and to characterize the proteases involved in this process. METHODS: Purified rhZP2, rhZP3 and rhZP4 proteins were incubated with capacitated sperm and the proteolytic activity was determined by Western blot analysis. To further characterize the proteases involved, parallel incubations were performed in the presence of the protease inhibitors o-phenanthroline, benzamidine and MG-132 meant to block the activity of metalloproteases, serine proteases and the proteasome, respectively. Additionally, protease inhibitors effect on sperm-ZP binding was evaluated by hemizona assay. RESULTS: The results showed that rhZPs were hydrolyzed in the presence of capacitated sperm. O-phenanthroline inhibited the degradation of rhZP3, MG-132 inhibited the degradation of rhZP4 and benzamidine inhibited the degradation of the three proteins under investigation. Moreover, hemizona assays demonstrated that sperm proteasome inhibition impairs sperm interaction with human native ZP. CONCLUSIONS: This study suggests that sperm proteasomes could participate in the degradation of ZP, particularly of the ZP4 protein. Besides, metalloproteases may be involved in specific degradation of ZP3 while serine proteases may contribute to unspecific degradation of the ZP. These findings suggest that localized degradation of ZP proteins by sperm is probably involved in ZP penetration and may be of help in understanding the mechanisms of fertilization in humans.
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Proteínas del Huevo/metabolismo , Fertilización/fisiología , Glicoproteínas de Membrana/metabolismo , Receptores de Superficie Celular/metabolismo , Capacitación Espermática/fisiología , Espermatozoides/metabolismo , Zona Pelúcida/metabolismo , Femenino , Humanos , Masculino , Oocitos/metabolismo , Glicoproteínas de la Zona PelúcidaRESUMEN
This work investigated the roles of the tetraamine thermospermine (TSpm) by analysing its contribution to Arabidopsis basal defence against the biotrophic bacterium Pseudomonas viridiflava. The participation of polyamine oxidases (PAOs) in TSpm homeostasis and TSpm-mediated defence was also investigated. Exogenous supply of TSpm, as well as ectopic expression of the TSpm biosynthetic gene ACL5, increased Arabidopsis Col-0 resistance to P. viridiflava, while null acl5 mutants were less resistant than Col-0 plants. The above-mentioned increase in resistance was blocked by the PAO inhibitor SL-11061, thus demonstrating the participation of TSpm oxidation. Analysis of PAO genes expression in transgenic 35S::ACL5 and Col-0 plants supplied with TSpm suggests that PAO 1, 3, and 5 are the main PAOs involved in TSpm catabolism. In summary, TSpm exhibited the potential to perform defensive functions previously reported for its structural isomer Spm, and the relevance of these findings is discussed in the context of ACL5 expression and TSpm concentration in planta. Moreover, this work demonstrates that manipulation of TSpm metabolism modifies plant resistance to pathogens.
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Arabidopsis/inmunología , Arabidopsis/microbiología , Resistencia a la Enfermedad/inmunología , Enfermedades de las Plantas/microbiología , Pseudomonas/fisiología , Espermina/análogos & derivados , Amina Oxidasa (conteniendo Cobre)/antagonistas & inhibidores , Amina Oxidasa (conteniendo Cobre)/metabolismo , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Resistencia a la Enfermedad/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genes de Plantas/genética , Oxidación-Reducción/efectos de los fármacos , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/antagonistas & inhibidores , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/genética , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/metabolismo , Pseudomonas/efectos de los fármacos , Pseudomonas/crecimiento & desarrollo , Putrescina/metabolismo , Espermina/metabolismo , Espermina/farmacología , Poliamino OxidasaRESUMEN
Polyamines have been globally associated to plant responses to abiotic stress. Particularly, putrescine has been related to a better response to cold and dehydration stresses. It is known that this polyamine is involved in cold tolerance, since Arabidopsis thaliana plants mutated in the key enzyme responsible for putrescine synthesis (arginine decarboxilase, ADC; EC 4.1.1.19) are more sensitive than the wild type to this stress. Although it is speculated that the over-expression of ADC genes may confer tolerance, this is hampered by pleiotropic effects arising from the constitutive expression of enzymes from the polyamine metabolism. Here, we present our work using A. thaliana transgenic plants harboring the ADC gene from oat under the control of a stress-inducible promoter (pRD29A) instead of a constitutive promoter. The transgenic lines presented in this work were more resistant to both cold and dehydration stresses, associated with a concomitant increment in endogenous putrescine levels under stress. Furthermore, the increment in putrescine upon cold treatment correlated with the induction of known stress-responsive genes, and suggested that putrescine may be directly or indirectly involved in ABA metabolism and gene expression.
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Aclimatación , Arabidopsis/metabolismo , Deshidratación , Congelación , Putrescina/metabolismo , Ácido Abscísico/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Dioxigenasas/metabolismo , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Estrés FisiológicoRESUMEN
We report a comparison of toxic and enzymatic activities of Bothrops alternatus venoms collected from specimens of different regions of Argentina with a pool of these same venoms. We determined lethal, hemorrhagic and pro-coagulant (plasma and fibrinogen) doses, as well as indirect hemolysis, hydrolysis of gelatin and fibrinogen. The electrophoretic pattern of the venoms and that of fibrinogen incubated with each of the venoms was studied by SDS-PAGE. The toxic activities were consistent with those reported for these venoms but with noticeable differences between samples which do not seem related to geographical or climatic characteristics. In some cases the pooled venom showed values close to the individual samples, but it was not representative since at least the half of the venoms (4/9) exhibited very different patterns of toxicity. The potency of some activities in the individual venoms ranged from much higher to much lower than those determined in the pooled venom (0.1 to 3 fold). Not all venoms exhibited thrombin-like activity but all hydrolyzed alpha and beta chains of fibrinogen; however, degradation patterns were not always similar. Variation in activities and toxicities do not seem to be related to geographical or climatic characteristics.
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Bothrops/fisiología , Venenos de Crotálidos/enzimología , Venenos de Crotálidos/toxicidad , Animales , Argentina , Coagulación Sanguínea/efectos de los fármacos , Bovinos , Venenos de Crotálidos/química , Electroforesis en Gel de Poliacrilamida , Fibrinógeno/efectos de los fármacos , Fibrinógeno/metabolismo , Gelatina/efectos de los fármacos , Gelatina/metabolismo , Hemorragia/inducido químicamente , Hemorragia/patología , Hidrólisis/efectos de los fármacos , Dosificación Letal Mediana , Ratones , Proteínas/análisis , Ratas , Ratas Wistar , Especificidad de la EspecieRESUMEN
Advanced food processing methods that accomplish inactivation of microorganisms but minimize adverse thermal exposure are of great interest to the food industry. High pressure (HP) and pulsed electric field (PEF) processing are commercially applied to produce high quality fruit and vegetable products in the United States, Europe, and Japan. Both microbial and plant cell membranes are significantly altered following exposure to heat, HP, or PEF. Our research group sought to quantify the degree of damage to plant cell membranes that occurs as a result of exposure to heat, HP, or PEF, using the same analytical methods. In order to evaluate whether new advanced processing methods are superior to traditional thermal processing methods, it is necessary to compare them. In this review, we describe the existing state of knowledge related to effects of heat, HP, and PEF on both microbial and plant cells. The importance and relevance of compartmentalization in plant cells as it relates to fruit and vegetable quality is described and various methods for quantification of plant cell membrane integrity are discussed. These include electrolyte leakage, cell viability, and proton nuclear magnetic resonance (¹H-NMR).
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Membrana Celular/metabolismo , Conservación de Alimentos/métodos , Frutas , Verduras , Membrana Celular/ultraestructura , Técnicas Electroquímicas , Frutas/química , Frutas/metabolismo , Frutas/microbiología , Frutas/ultraestructura , Calor/efectos adversos , Presión Hidrostática/efectos adversos , Viabilidad Microbiana , Control de Calidad , Verduras/química , Verduras/metabolismo , Verduras/microbiología , Verduras/ultraestructuraRESUMEN
Tityus trivittatus is the Argentinean scorpion reported to cause the majority of human fatalities in the country, however no systematic studies have been conducted with the venom of this species. This communication describes a general biochemical and immunological characterization of the venom obtained from T. trivittatus scorpions collected in the city of Buenos Aires and various provinces of Argentina: Catamarca, Cordoba, Entre Rios, La Rioja, Santa Fe and Santiago del Estero. These are places where human accidents were reported to occur due to this scorpion. For comparative purposes two types of samples were assayed: whole soluble venom obtained by electrical stimulation and supernatant from homogenized venomous glands. Two strains of mice (NIH and CF-1) were used for LD(50) determinations by two distinct routes of administration (intravenously and intraperitoneally). Important variations were found that goes from 0.5 to 12 mg/kg mouse body weight. Samples of soluble venom were always more potent than Telson homogenates. More complex pattern was observed in homogenates compared to soluble venom, as expected. This was supported by gel electrophoretic analysis and high performance liquid chromatographic (HPLC) separations. Additionally, the HPLC profile was enriched in proteins resolved at similar elution times as other known toxins from scorpion venoms studied. Immune enzymatic assays were also conducted comparatively, using four different anti-venoms commercially available for treatment of scorpion stings (Argentinean antidote from INPB, two anti-venoms from Butantan Institute of Brazil and Alacramyn from the Mexican Bioclon Institute). Cross-reactivities were observed and are reported among the various venoms and anti-venoms used. Lung, heart, liver and pancreas pathological modifications were observed on tissues of intoxicated mice. It seems that there are important variations on the venom compositions of the various samples studied and reported here, depending on the geographical area where the scorpions were captured. The results reported here are important for the clinical outcome of human accidents.
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Venenos de Escorpión/química , Venenos de Escorpión/inmunología , Animales , Antivenenos/química , Argentina , Estimulación Eléctrica , Electroforesis en Gel de Poliacrilamida , Ensayo de Inmunoadsorción Enzimática , Glándulas Exocrinas/química , Inmunoprecipitación , Inyecciones Intraperitoneales , Inyecciones Intravenosas , Dosificación Letal Mediana , Hígado/patología , Pulmón/patología , Ratones , Miocardio/patología , Venenos de Escorpión/toxicidad , EscorpionesRESUMEN
A study on polyamine metabolism and the consequences of polyamine biosynthesis inhibition on the development of Sclerotinia sclerotiorum sclerotia was conducted. Concentrations of the triamine spermidine and the tetramine spermine, as well as ornithine decarboxylase and S-adenosyl-methionine decarboxylase activities, decreased during sclerotia maturation. In turn, the concentration of the diamine putrescine was reduced at early stages of sclerotial development but it increased later on. This increment was not related to de novo biosynthesis, as demonstrated by the continuous decrease in ornithine decarboxylase activity. Alternatively, it could be explained by the release of putrescine from the conjugated polyamine pool. Alpha-difluoro-methylornithine and cyclohexylamine, which inhibit putrescine and spermidine biosynthesis, respectively, decreased mycelial growth, but did not reduce the number of sclerotia produced in vitro even though they disrupted polyamine metabolism during sclerotial development. It can be concluded that sclerotial development is less dependent on polyamine biosynthesis than mycelial growth, and that the increase of free putrescine is a typical feature of sclerotial development. The relationship between polyamine metabolism and sclerotial development, as well as the potential of polyamine biosynthesis inhibition as a strategy for the control of plant diseases caused by sclerotial fungi are discussed.