30 research outputs found
Coral Reef Bleaching: An Ecological and Biological Overview
Coral reefs are central to the biology of our planet, but in the past few decades, they have suffered a severe decline due to a variety of natural and anthropogenic disturbances. On a worldwide scale, the main disturbance is bleaching, which can be defined as the loss of endosymbiotic dinoflagellates and/or of their photosynthetic pigments from their cnidarian host; with that, the normal pigmentation of the tissue of cnidarians is generally lost and the white calcium carbonate skeleton becomes visible through the transparent tissue of the host. Coral bleaching can be triggered by multiple factors, but most of the bleaching observed in the field is a result of elevated sea surface temperature. It has been widely documented that bleaching is deleterious to coral reefs, significantly altering the biological and ecological processes that maintain reef communities; yet populations resistant to climate change have recently been identified, and it has been reported that acclimatization occurs in less than two years. The aim of this review is to provide upâtoâdate information regarding cnidarianâdinoflagellate symbiosis; causes of coral bleaching; mechanisms underlying this phenomenon; consequences of bleaching; and the survival mechanisms by which coral reefs face this threat
Vasodilator Activity of Compounds Isolated from Plants Used in Mexican Traditional Medicine
Abstract: Arterial hypertension is one of the main risk factors in the development of cardiovascular diseases. Therefore, it is important to look for new drugs to treat hypertension. In this study, we carried out the screening of 19 compounds (triterpenes, diterpenes, sesquiterpenes, lignans, and ïŹavonoids) isolated from 10 plants used in Mexican traditional medicine to determine whether they elicited vascular smooth muscle relaxation and, therefore, could represent novel anti-hypertension drug candidates. The vasorelaxant activity of these compounds was evaluated on the isolated rat aorta assay and the results obtained from this evaluation showed that three compounds induced a signiïŹcant vasodilatory effect: meso-dihydroguaiaretic acid [half maximal effective concentration (EC50), 49.9 ± 11.2 ”M; maximum effect (Emax), 99.8 ± 2.7%]; corosolic acid (EC50, 108.9 ± 6.7 ”M; Emax, 96.4 ± 4.2%); and 5,8,40-trihydroxy-3,7-dimethoxyïŹavone (EC50, 122.3 ± 7.6 ”M; Emax, 99.5 ± 5.4%). Subsequently, involvement of the NO/cyclic guanosine monophosphate (cGMP) and H2S/ATP-sensitive potassium channel (KATP) pathways on the vasodilator activity of these compounds was assessed. The results derived from this analysis showed that the activation of both pathways contributes to the vasorelaxant effect of corosolic acid. On the other hand, the vasodilator effect of meso-dihydroguaiaretic acid and 5,8,40-trihydroxy-3,7-dimethoxyïŹavone, partly involves stimulation of the NO/cGMP pathway. However, these compounds also showed an important endothelium-independent vasorelaxant effect, whose mechanism of action remains to be clariïŹed. This study indicates that meso-dihydroguaiaretic acid,corosolicacid,and5,8,40-trihydroxy-3,7-dimethoxyïŹavonecouldbeusedasleadcompoundsfor the synthesis of new derivatives with a higher potency to be developed as drugs for the prevention and treatment of cardiovascular diseases.
Keywords: corosolic acid; 5,8,40-trihydroxy-3,7-dimethoxyïŹavone; meso-dihydroguaiaretic acid hydrogen sulïŹde; nitric oxide; vasorelaxatio
Impact of El Niño-Southern Oscillation 2015-2016 on the soluble proteomic profile and cytolytic activity of Millepora alcicornis (âfire coralâ) from the Mexican Caribbean
Reef-forming cnidarians are extremely susceptible to the âbleachingâ phenomenon caused by global warming. The effect of elevated seawater temperature has been extensively studied on Anthozoans; however, to date the impact of thermal stress on the expression of genes and proteins in Hydrozoan species has not been investigated. The present study aimed to determine the differential proteomic profile of Millepora alcicornis, which inhabits the Mexican Caribbean, in response to the El Niño-Southern Oscillation 2015â2016. Additionally, the cytolytic activity of the soluble proteomes obtained from normal and bleached M. alcicornis was assessed. Bleached specimens showed decreased symbiontâs density and chlorophyll a and c2 levels. After bleaching, we observed a differential expression of 17 key proteins, tentatively identified as related to exocytosis, calcium homeostasis, cytoskeletal organization, and potential toxins, including a metalloprotease, a phospholipase A2 (PLA2), and an actitoxin. Although, some of the differentially expressed proteins included potential toxins, the hemolytic, PLA2, and proteolytic activities elicited by the soluble proteomes from bleached and normal specimens were not significantly different. The present study provides heretofore-unknown evidence that thermal stress produces a differential expression of proteins involved in essential cellular processes of Hydrozoan species. Even though our results showed an over-expression of some potential toxin-related proteins, the cytolytic effect (as assessed by hemolytic, PLA2, and caseinolytic activities) was not increased in bleached M. alcicornis, which suggests that the cytolysis is mainly produced by toxins whose expression was not affected by temperature stress. These findings allow hypothesizing that this hydrocoral is able to prey heterotrophically when suffering from moderate bleaching, giving it a better chance to withstand the effects of high temperature
4to. Congreso Internacional de Ciencia, TecnologĂa e InnovaciĂłn para la Sociedad. Memoria acadĂ©mica
Este volumen acoge la memoria acadĂ©mica de la Cuarta ediciĂłn del Congreso Internacional de Ciencia, TecnologĂa e InnovaciĂłn para la Sociedad, CITIS 2017, desarrollado entre el 29 de noviembre y el 1 de diciembre de 2017 y organizado por la Universidad PolitĂ©cnica Salesiana (UPS) en su sede de Guayaquil.
El Congreso ofreciĂł un espacio para la presentaciĂłn, difusiĂłn e intercambio de importantes investigaciones nacionales e internacionales ante la comunidad universitaria que se dio cita en el encuentro. El uso de herramientas tecnolĂłgicas para la gestiĂłn de los trabajos de investigaciĂłn como la plataforma Open Conference Systems y la web de presentaciĂłn del Congreso http://citis.blog.ups.edu.ec/, hicieron de CITIS 2017 un verdadero referente entre los congresos que se desarrollaron en el paĂs.
La preocupaciĂłn de nuestra Universidad, de presentar espacios que ayuden a generar nuevos y mejores cambios en la dimensiĂłn humana y social de nuestro entorno, hace que se persiga en cada ediciĂłn del evento la presentaciĂłn de trabajos con calidad creciente en cuanto a su producciĂłn cientĂfica.
Quienes estuvimos al frente de la organizaciĂłn, dejamos plasmado en estas memorias acadĂ©micas el intenso y prolĂfico trabajo de los dĂas de realizaciĂłn del Congreso Internacional de Ciencia, TecnologĂa e InnovaciĂłn para la Sociedad al alcance de todos y todas
Abstracts from the 8th International Conference on cGMP Generators, Effectors and Therapeutic Implications
This work was supported by a restricted research grant of Bayer AG
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprungâs disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprungâs disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36â39) and median bodyweight at presentation was 2·8 kg (2·3â3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
pâ€0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88â4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59â2·79], p<0·0001), sepsis at presentation (1·20
[1·04â1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4â5 vs ASA 1â2, 1·82 [1·40â2·35], p<0·0001; ASA 3 vs ASA 1â2, 1·58, [1·30â1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02â1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41â2·71], p=0·0001; parenteral nutrition 1·35, [1·05â1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47â0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50â0·86], p=0·0024) or percutaneous central line (0·69 [0·48â1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Vasodilation Elicited by Isoxsuprine, Identified by High-Throughput Virtual Screening of Compound Libraries, Involves Activation of the NO/cGMP and H2S/KATP Pathways and Blockade of α1-Adrenoceptors and Calcium Channels
Recently, our research group demonstrated that uvaol and ursolic acid increase NO and H2S production in aortic tissue. Molecular docking studies showed that both compounds bind with high affinity to endothelial NO synthase (eNOS) and cystathionine gamma-lyase (CSE). The aim of this study was to identify hits with high binding affinity for the triterpene binding-allosteric sites of eNOS and CSE and to evaluate their vasodilator effect. Additionally, the mechanism of action of the most potent compound was explored. A high-throughput virtual screening (HTVS) of 107,373 compounds, obtained from four ZINC database libraries, was performed employing the crystallographic structures of eNOS and CSE. Among the nine top-scoring ligands, isoxsuprine showed the most potent vasodilator effect. Pharmacological evaluation, employing the rat aorta model, indicated that the vasodilation produced by this compound involved activation of the NO/cGMP and H2S/KATP signaling pathways and blockade of α1-adrenoceptors and L-type voltage-dependent Ca2+ channels. Incubation of aorta homogenates in the presence of isoxsuprine caused 2-fold greater levels of H2S, which supported our preliminary in silico data. This study provides evidence to propose that the vasodilator effect of isoxsuprine involves various mechanisms, which highlights its potential to treat a wide variety of cardiovascular diseases