Glycolipids from Sargassum filipendula, a Natural Alternative for Overcoming ABC Transporter-Mediated MDR in Cancer.

Chemotherapy is a widely used strategy to treat cancer, a disease that causes millions of deaths each year. However, its efficacy is reduced by the overexpression of ABC transporters, which are proteins that expel the drugs used in chemotherapy and involved in the multidrug resistance (MDR). Glycolipids have been identified as potential inhibitors of ABC transporters. Algae of the genus Sargassum contain high levels of glycolipids, making them a promising therapeutic alternative against the MDR phenotype. Sargassum filipendula glycolipids were obtained by exhaustive maceration with chloroform/methanol, purified by column and thin layer chromatography, and then characterized by FTIR, NMR, and LC-MS. Cell viability by PI labeling and inhibition of ABC transporters were analyzed by flow cytometry. Assessment of resistance reversal was determined by MTT assay. Ten sulfoquinovosylglycerol-type compounds were found, and six of them are reported for the first time. In particular, moiety 4 (GL-4) showed strong and moderate inhibitory activity against ABCC1 and ABCB1 transporters respectively. Treatment of GL-4 in combination with the antineoplastic drug vincristine sensitized Lucena-1 cell model to drug and reversed the MDR phenotype. This is the first report of glycolipids isolated from S. filipendula capable of inhibiting ABC transporters and thus overcoming acquired drug resistance.

Sargassum filipendula, a Source of Bioactive Compounds with Antioxidant and Matrix Metalloproteinases Inhibition Activities In Vitro with Potential Dermocosmetic Application.

The antioxidant and the potential inhibitory capacity of matrix metalloproteinases of the phlorotannin-type polyphenolic and fucoidan-type polysaccharides extracts obtained from the macroalga S. filipendula were evaluated. Through chromatographic and spectroscopic techniques, the corresponding chemical structure of compounds present in the extracts was determined. Antioxidant capacity was evaluated using the methyl linoleate model for the inhibition of lipid peroxidation, and the free radical scavenging capacity was assessed using DPPH, ABTS, •OH, O2•- methods. The matrix metalloproteinase inhibition potential was measured by collagenase and elastase inhibition tests, using epigallocatechin gallate as a positive control. The extracts exhibited a high scavenging capacity of radical species evaluated and inhibition of diene conjugate formation and thiobarbituric acid reactive substances. The results showed that the crude extracts presented dose-dependent collagenase and elastase inhibition, with IC50 values between 0.04 and 1.61 mg/mL. The structure of the residues of the polysaccharide was identified mainly as (1→3)-sulfated (1→3) α-l-fucopyranose at carbon 4 and residues of ß-d-glucopyranose, α-d-Mannopyranose, and ß-d-Galactopyranose, while in the polyphenol extract the presence of phloroglucinol was identified and the presence of eckol, bifuhalol, and trifuhalol was suggested. Our results allow us to infer that S. filipendula is a potential source of bioactive ingredients with antioxidant and anti-aging activity.

Anticancer and Antioxidant Activity of Water-Soluble Polysaccharides from Ganoderma aff. australe against Human Osteosarcoma Cells.

Wild mushrooms have gained great importance for being a source of biologically active compounds. In this work, we evaluate the anticancer and antioxidant activity of a water-soluble crude polysaccharide extract isolated from the fruiting bodies of the Ganoderma aff. australe (GACP). This mushroom was collected in San Mateo (Boyacá, Colombia) and identified based on macroscopic and microscopic characterization. GACP was characterized by UV-Vis spectroscopy, Fourier-transform infrared spectroscopy, high-performance liquid chromatography-diode array detector, and nuclear magnetic resonance. The antiradical and antioxidant activity were evaluated by different methods and its anticancer activity was verified in the osteosarcoma MG-63 human cell line. Chemical and spectroscopic analysis indicated that GACP consisted of ß-D-Glcp-(1→, →3)-ß-D-Glcp-(1→ and α-D-Glcp-(1→ residues. The results of the biological activity showed that GACP exhibited high antioxidant activity in the different methods and models studied. Moreover, the results showed that GACP impaired cell viability (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay) and cell proliferation (clonogenic assay) in a dose-response manner on MG-63 cells. The findings of this work promote the use of mushroom-derived compounds as anticancer and antioxidant agents for potential use in the pharmaceutical and food industries.

Hedinger Syndrome with Intraoperative Carcinoid Crisis — Understanding the Pathophysiology for a Successful Management

Abstract Carcinoid tumors can be a cause for right heart valve disease, also known as Hedinger syndrome or carcinoid heart disease. Proper understanding of the pathophysiology is of the uttermost importance for adequate treatment of these patients, especially during heart surgery.

Lentinula edodes, a Novel Source of Polysaccharides with Antioxidant Power.

The fruiting bodies of edible mushrooms represent an important source of biologically active polysaccharides. In this study, Lentinula edodes crude polysaccharides (LECP) were extracted in hot water, and their antioxidant and antiradical activities were investigated. The antioxidant activity of LECP was investigated against reactive species such as 1,1'-diphenyl-2-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, hydroxyl and superoxide anion radicals, reducing power with EC50 values of 0.51, 0.52, 2.19, 3.59 and 1.73 mg/mL, respectively. Likewise, LECP inhibited the lipid peroxidation induced in methyl linoleate through the formation of conjugated diene hydroperoxide and malondialdehyde. The main sugar composition of LECP includes mannose, galactose, glucose, fucose and glucuronic acid. Characterization by Fourier transform infrared spectroscopy and nuclear magnetic resonance determined that LECP was made up of α and ß glycosidic bonds with a backbone of α-D-Glc, →6)-ß-D-Glcp-(1→, →6)-α-D-Galp-(1→ and ß-D-Manp-(1→ residues. The results showed that LECP can scavenge all reactive species tested in a concentration-dependent manner and with a protective effect in the initial and final stages of lipid peroxidation. The natural antioxidant activity of the LECP that was investigated strengthens the high medicinal and nutritional value of this mushroom.

Hedinger Syndrome with Intraoperative Carcinoid Crisis - Understanding the Pathophysiology for a Successful Management.

Carcinoid tumors can be a cause for right heart valve disease, also known as Hedinger syndrome or carcinoid heart disease. Proper understanding of the pathophysiology is of the uttermost importance for adequate treatment of these patients, especially during heart surgery.

Algae Metabolites as an Alternative in Prevention and Treatment of Skin Problems Associated with Solar Radiation and Conventional Photo-protection

Abstract The histological structure and biochemistry of the skin is affected by solar radiation having adverse effects ranging from sunburns, premature aging that includes wrinkles, spots, dryness, and loss of collagen to cancer development. The skin has defense mechanisms to prevent damage caused by radiation, but when radiation exposure is excessive these mechanisms are not strong enough to protect the skin. The use of sunscreen is the most common practice of photo- protection. The active ingredients of these cosmetic protective formulations are generally from synthetic origin and have presented several drawbacks at the level of photo-stability, systemic absorption and can generate contact and photo-contact dermatitis. This review illustrates skin solar radiation problems, common sunscreen ingredients limitation and mentions how algae can be an alternative according to studies that have evaluated the photo-protective potential of extracts and compounds isolated by different techniques.

In vitro UV absorption properties and radical scavenging capacity of Morella parvifolia (Benth. ) Parra-Os. extracts

The goal of this research was to identify major compounds of the aerial parts of M. parvifolia (Benth.) Parra-Os., that could enhance its possible application as additive in dermocosmetic products, as well as evaluate the antioxidant properties. The extracts agreed with the broad-spectrum UVB/UVA absorption detected and could act as broad-spectrum sunscreens, covering the UVA and UVB range. Methanolic extracts showed an important antiradical capacity (0.46 and 0.47 g/µmol DPPH), TPC (37.58 and 51.41mg GAE/g DS) and TAC (1.12 and 3.31 mg C3GE/g DS) in fruits and leaves, respectively. M. parvifolia could be considered as a prospective source of natural UV-radiation absorbers with antioxidant capacity. Although the results have clearly demonstrated the potential photoprotection capacity, more studies are needed to enhance its application as an additive in pharmaceutical and medicinal formulations.

Disrupción auriculoventricular posterior a reoperación de reemplazo valvular mitral: reparación y evaluación ecocardiográfica / Atrioventricular disruption posterior to reoperation of mitral valve replacement: repair and echocardiographic evaluation

La disrupción auriculoventricular después del reemplazo valvular mitral es una rara pero letal complicación. Este caso es el de una mujer de 72 años de edad, con antecedentes de: reemplazo valvular aórtico, mitral, plastia tricúspide y Maze. Se llevó al reemplazo valvular mitral con prótesis Hancock 29 mitral. Se trasladó a la UCI y el curso postoperatorio fue normal hasta las 24 horas después de la cirugía, cuando presentó disnea y requirió soporte inotrópico. Se le realizó un angiotac y un ecocardiograma transtorácico que evidenció pseudoaneurisma ventricular. Fue llevada a cirugía, se inició circulación extracorpórea. Se evidenció disrupción auriculoventricular en el anillo posterior de la válvula mitral (tipo I perforación). La ruptura fue cerrada con un parche mixto de pericardio bovino y dacron con sutura continua. Actualmente, la paciente está en buenas condiciones sin recurrencia. Investigamos: el caso, la etiología, el reparo quirúrgico y la prevención de esta rara complicación y se discute.

Atrioventricular disruption after a mitral valve replacement is a rare but fatal complication. A case of 72 year-old woman is presented. She had a medical history of aortic and mitral valve replacement and Maze and tricuspid valve surgery. Mitral valve replacement was performed with Hancock 29 mitral prosthesis. She was taken to ICU and postoperative progress was normal until 24 hours after the surgery, when she developed dyspnea and required inotropic support. A CT angiography and transthoracic echocardiogram were performed, which evidence a ventricular pseudoaneurysm. She was taken to the operating room to start extracorporeal circulation. Atrioventricular disruption was evidenced in the posterior mitral annulus (type I perforation). Rupture was closed with a using a mixed Dacron and bovine pericardial patch with continuous suture. Patient is currently in good condition with no recurrence. Case, etiology, surgical repair and prevention of this rare complication were investigated and discussed.

Disfunción renal en postoperatorio de cirugía cardíaca pediátrica con circulación extracorpórea / Renal dysfunction in postoperative of pediatric heart surgery with circulation extracorpórea

Objetivos: La disfunción renal en el postoperatorio de la cirugía cardiaca continúa aumentando la morbilidad, mortalidad y costos. Aunque se han realizado múltiples estudios, los factores asociados a esta no están claros en el grupo pediátrico. El propósito del estudio es determinar la incidencia de disfunción renal postoperatoria, factores de riesgo para su desarrollo, su asociación a la mortalidad y las estancias hospitalarias. Métodos: Se estudiaron de forma prospectiva 236 pacientes, menores de 12 años de llevados a cirugía cardiaca con circulación extracorpórea entre el 1 de mayo del 2000 y el 31 de julio del 2003. Fueron excluidos los pacientes llevados a cierre de CIA y los que fallecieron en las primeras 24 horas. Se evaluó la asociación de las variables pre, trans y postoperatorias al desarrollo de disfunción o falla renal por medio de análisis univariado y multivariado. Se definió disfunción como valores anormales de depuración de creatinina para la edad, aumento del 25 por ciento de la creatinina basal u oliguria y falla como el requerimiento de diálisis. Resultados: De los 236 pacientes el 72 por ciento presento disfunción renal y 4,2 por ciento desarrolló falla renal. La única variable asociada al desarrollo de disfunción renal fue el hematocrito postoperatorio con una relación positiva: P = 0.001. Conclusiones: La disfunción renal esta asociada de forma independiente con la mortalidad postoperatoria de estos pacientes y con el aumento de las estancias en UCI y la estancia hospitalaria...

¿Costo-efectividad? / Cost-effectiveness?

Vivimos una época de cambio en nuestro ejercicio profesional que nos obliga a enfrentarnos a una nueva forma de ejercer la profesión. Nuestro ejercicio médico sustentado en bases pura-mente científicas y con claros objetivos sociales está dejando de existir y los administradores dela salud nos obligan a ver esta como un negocio. Esta situación puede ser vista inicialmente como una amenaza para nuestro desarrollo cien-tífico y asistencial; sin embargo, se ha convertido en una oportunidad importante de mejoría en la atención médica.

We are living in a time of change in our professional practice that forces us to face a new way of practicing the profession. Our medical practice, based on purely scientific grounds and with clear social objectives, is ceasing to exist and health administrators are forcing us to see it as a business. This situation may initially be seen as a threat to our scientific and healthcare development; however, it has become an important opportunity for improvement in medical care.

Efecto vasodilatador del levosimendan sobre los conductos arteriales utilizados en cirugía de revascularización coronaria / Vasodilator effect of the levosimendan on the arterial conduits utilized in surgery of revascularización coronary

Introducción: El levosimendan es un derivado piridazona y dinitrilo que incrementa la contracción miocárdica al estabilizar la unión del Ca y con la troponina C. Es también un vasodilatador sistémico y pulmonar. Ha sido utilizado exitosamente para tratar los estados de bajo gasto cardiaco luego de bypass cardiopulmonar. Sin embargo, es desconocido si puede utilizarse para el tratamiento del espasmo intraoperatorio de puentes coronarios. El propósito de este estudio es investigar los efectos in vitro del levosimendan sobre las arterias mamarias internas (AMI) humanas con el fin de obtener evidencia científica antes de su aplicación clínica. Métodos: Se tomaron segmentos de AMI de 85 pacientes sometidos a revascularización miocádica. El segmento distal se cortó en anillos de 3 mm de longitud que se extendieron hasta su óptima tensión de reposo, en cámaras orgánicas que contenían 25 ml de solución de Krebs, a 37 C y aireados con 95 por ciento de O2 y 5 por ciento de CO2. Luego de un periodo de equilibrio se constriñeron con norepinefrina (10 y 5.5 M) o análogo de tromboxano A2 U46619 (10 y 8 M). Se adicionaron de forma acumulativa, Nitroglicerina (NTG), milrinone (MIL) y levosimendan (LEV) para relajar las preparaciones, construyéndose curvas dosis y respuesta. En experimentos paralelos, la presencia o ausencia de endotelio funcional fue evaluada por la repuesta a acetil y colina (10 y 6 M) en anillos precontraidos con NE (10 y 5.5 M), sometiendose posteriormente a relajación con LEV. Resultados: Concentraciones incrementadas de NTG, MIL y LEV relajaron los segmentos de AMI constreñidos con NE o U46619, sin diferencia en anillos con y sin endotelio. Conclusiones: El levosimendan produjo una relajación, dependiente de la concentración, de anillos de AMI, similar a la obtenida con otros vasodilatadores. Su combinación de inotrópico positivo y vasodilatador puede ser beneficioso en el tratamiento perioperatorio del vasoespasmo en pacientes sometidos a revascularización miocárdica...