Gold Nanoparticles Modification with Liquid Crystalline Polybenzylic Dendrons via 1,3-Dipolar Cycloaddition.

A series of six polybenzylic dendrons with an alkynyl focal point were synthesized for their incorporation to gold nanoparticles. Five of these compounds showed columnar mesomorphism in a wide range of temperatures. These dendrons were reacted with gold nanoparticles stabilized with a combination of a dodecanethiol and 11-azidoundecane-1-thiol. The azido group of the last compound allowed the functionalization of the nanoparticles with the six polybenzylic dendrons by 1,3-dipolar cycloaddition between their alkynyl groups and the terminal azido groups of the thiols. A high efficiency of the cycloaddition process (47-69%) was confirmed by several experimental techniques and no decomposition or aggregation phenomena were detected in the dendron-coated nanoparticles. The involved mechanism and the resulting percentage composition of the final materials are discussed. The results of the ulterior growth of the nanoparticles by thermal treatment are influenced by the size and the shape of the dendron and the temperature of the process. The structures of the final nanoparticles were investigated by TEM, DSC, TGA, NMR and UV-Vis spectroscopy. These nanoparticles do not show liquid crystal properties. However, a melting process between a crystalline and a fluid phase is observed. In the solid phase, the nanomaterials prepared show a short-range interaction between nanoparticles with a 2D local hexagonal order. A near-field effect was observed in the UV-vis spectra by coupling of different surface plasmon resonance bands (SPR) probably due to the short-range interactions. The main novelty of this work lies in the scarcity of previous studies of gold nanoparticles coated with dendrons forming themselves columnar mesophases. Most of the studies reported in the literature deal with gold nanoparticles coated with calamitic mesogens. Additionally, the effect of the thermal treatment, which in a previous paper was shown to increase the mean size of the nanoparticles without increasing their size polydispersity, has been studied in these materials.

Experiencia del empleo sistemático de la dieta de muy bajo valor calórico para la optimización en el preoperatorio de cirugía bariátrica / Experience of the systemic use of the very low caloric value diet for the optimization in the preoperatory of bariatric surgery

Resumen Introducción: La cirugía bariátrica no está exenta de complicaciones. Para minimizar dichas complicaciones es importante optimizar al paciente antes de la cirugía. Dicha optimización se basa fundamentalmente en la realización de dieta preoperatoria. Dentro de los múltiples tipos de dietas, la dieta de muy bajo valor calórico (DMBVC) es cada vez más utilizada. El objetivo de este estudio es analizar los resultados del empleo de la DMBVC en el preoperatorio de cirugía bariátrica. Método: Estudio observacional de una serie de 100 casos en los que se empleó la DMBVC como optimización preoperatoria. Se analizaron el grado de cumplimiento de la dieta, la opinión de los pacientes, la pérdida de peso preoperatoria y las complicaciones postoperatorias. Resultados: La pérdida de peso preoperatoria media fue de 10,2 kg y la disminución media del IMC fue de 4,8. En cuanto al grado de seguimiento, el 68% refirió que la cumplió estrictamente, el 22% manifestó un buen grado de seguimiento con alguna transgresión ocasional, el 8% reportó un mal seguimiento y el 1% la abandonó precozmente. No se presentaron efectos adversos significativos. En cuanto a la técnica quirúrgica, en ningún caso el volumen hepático dificultó la cirugía, con un 0% de conversiones y un tiempo medio operatorio de 60 min. En el postoperatorio inmediato se registraron un 4% de sangrado y un 1% de reintervención por hemoperitoneo. Conclusiones: Las DMBVC son sencillas de utilizar, con escasos efectos adversos, bien toleradas durante un periodo limitado de tiempo, obteniendo una adecuada pérdida ponderal preoperatoria.

Abstract Introduction: Bariatric surgery may have some complications. To minimize such complications is important to optimize the patient before surgery. Such optimization is based primarily on the performance of preoperative diet. Among the many types of diets, very low caloric diet (VLCD) is increasingly used. The aim of this study is to analyze the results of the use of VLCD preoperative bariatric surgery. Method: Observational study of a series of 100 cases in which the DMBVC was used as a preoperative optimization. The degree of compliance with the diet, the opinion of patients, preoperative weight loss and postoperative complications were analyzed. Results: The mean preoperative weight loss was 10.2 kg and the average BMI decrease of 4.8. As for the degree of compliance, 68% said that the strictly fulfilled, 22% follow up with a good degree occasional transgression, mistracking 8% and 1% abandoned early. No significant adverse effects occurred. Regarding the surgical technique, in any case difficult surgery liver volume, with 0% conversion and an average operating time of 60 min. In the immediate postoperative period 4% cases of reoperation for bleeding and 1% hemoperitoneum were reported. Conclusions: DMBVC are simple to use, with few adverse effects, well tolerated for a limited period of time, obtaining adequate preoperative weight loss.

Liposarcoma retroperitoneal complicado: a propósito de un caso / Complicated retroperitoneal liposarcoma: a case report

Resumen Las neoplasias retroperitoneales suponen un reto para el profesional sanitario, tanto en el diagnóstico como en el tratamiento. Caso clínico: Varón de 56 años diabético tipo 2. Acude por edema en extremidad inferior derecha y parestesias. Se realiza ecografía doppler con resultados de trombosis venosa profunda y conglomerado adenopático. En TAC abdominal se observa gran masa retroperitoneal que engloba paquete vasculonervioso iliaco derecho. Se realiza vaciamiento ganglionar con resultado inicial de hamartoma. Se practica cirugía de resección de la masa y ligadura de la vena iliaca externa trombosada preservando la arteria iliaca. Anatomía patológica intraoperatoria sugestiva de sarcoma y definitiva de liposarcoma. Reingresa por shock hipovolémico y rotura de la arteria iliaca derecha. Se realiza ligadura y bypass femoro-femoral izquierdo-derecho. Al alta es derivado a oncología, falleciendo a los 6 meses. Discusión: El sarcoma es el tumor primario más frecuente a nivel retroperitoneal (15%). De difícil diagnóstico y tardío tratamiento, suelen ser asintomáticos hasta que debutan como una masa y clínica de compresión local o afectación de estructuras vasculonerviosas. El TAC es la prueba diagnóstica de elección. El tratamiento del tumor localizado es la cirugía; la radioterapia y quimioterapia se reservan para tumores irresecables o de alto grado.

Abstract Retroperitoneal neoplasias may be a diagnostic and therapeutic challenge for the clinician. Case report: A 56 year old male with prior history of type 2 diabetes consults with right inferior limb edema and paresthesias. He was diagnosed of deep vein thrombosis and lymph node conglomerate by ultrasound. A CT scan was performed, observing great retro peritoneal mass enclosing vascular and nervous structures. An initial histological diagnosis of hamartoma was made. Surgery was scheduled to remove the tumour, ligation of thrombosed external iliac vein and the external iliac artery was preserved. Intraoperative histological findings suggested sarcoma, definite studies showed presence of high grade liposarcoma. Two weeks after the intervention, the patient presents in hypovolemic shock due to rupture of the right external iliac artery. Emergent ligation of the artery and femorofemoral bypass was performed, with adequate postoperatory recovery. The patient was discharged and continued adjuvant oncology treatment and was exitus six months later. Discussion: Sarcomas are the most frequent primary retroperitoneal tumours. They are difficult to diagnose and often have untimely treatment. Sarcomas tend to be asymptomatic, or present with local compression symptoms, affecting vascular and nervous structures. CT scan is the gold standard for diagnostic imaging. Treatment requires a multidisciplinary approach, surgical resection as the main therapy; radio and chemotherapy represents a solution for irresectable or high grade malignancies.

[Risk factors associated with the diagnosis of chronic Chagasic miocardiopathy in seropositive individuals from Barinas state, Venezuela]. / Factores de riesgo asociados con el diagnóstico de miocardiopatía chagásica crónica en individuos seropositivos del estado Barinas, Venezuela.

This study evaluates the risk factors associated with the diagnosis of chronic chagasic miocardiopathy (CChM) in 115 seropositive individuals to anti-Trypanosoma cruzi antibodies, in Barinas state, Venezuela. Serology was performed with ELISA and MABA; while the CChM diagnosis was established by electrocardiography and echocardiography. A complete clinical history including epidemiological, personal/familiar antecedents and psychobiological habits, plus socioeconomic, psychosocial and alimentary habits interviews were performed for each individual. Risk factors were determined through binary logistic regression. Results showed that 81 patients (70,4%; CI 95% = 66.4-74.4) had criteria for CChM, of which 74 (64.4%; IC 95% = 60.2-68.6) were in phase II; while 34 (29.6%; IC 95% = 25.5-33.5) were in phase I of the disease and 7 (6.1%; IC 95% = 4.0-8.2) in phase III. In a one year period, two patients in phase III died of heart failure. The diagnosis of CChM was associated with hunting practice, maternal history of cardiopathies, chewing chimó, medical history of hypertension and apex beat visible; it was negatively associated with canned and preserved foods ingest. In conclusion the CChM diagnosis has high frequency in seropositive individuals in Barinas and heart failure prevention must be based on an early medical attention and educative strategies in order to control risk factors.

Factores de riesgo asociados con el diagnóstico de miocardiopatía chagásica crónica en individuos seropositivos del estado Barinas, Venezuela / Risk factors associated with the diagnosis of chronic chagasic miocardiopathy in seropositive individuals from Barinas state, Venezuela

Se determinaron los factores de riesgo asociados al diagnóstico de miocardiopatía chagásica crónica (MChC) en 115 individuos seropositivos para anticuerpos anti-Trypanosoma cruzi, en el Estado Barinas, Venezuela. La seropositividad fue determinada mediante ELISA y MABA (Multiple Antigen Blot Assay) y el diagnóstico de MChC fue establecido mediante electrocardiografía y ecocardiografía. A cada individuo se le realizó una historia clínica completa que incluyó antecedentes epidemiológicos, antecedentes patológicos personales y familiares, y hábitos psicobiológicos; además se realizó una encuesta donde se interrogó acerca de factores de riesgo socioeconómicos, psicosociales y de hábitos alimentarios. Los factores de riesgo fueron establecidos mediante una regresión logística binaria. Los resultados mostraron que 81 (70,4%; IC95% = 66,4-74,4) pacientes reunían criterios para el diagnóstico de MChC, de los cuales 74 (64,4%; IC95% = 60,2-68,6) estaban en Fase II (6,1%; IC95% = 4,0-8,2) y 7 en Fase III, mientras que 34 (29,6%; IC95% = 25,5-33,5) estaban en Fase I. En el periodo de 1 año murieron 2 individuos en Fase III. El diagnóstico de MChC estuvo asociado con la práctica de la caza de animales silvestres, el consumo de chimó, antecedentes maternos de cardiopatía, antecedentes personales de hipertensión arterial y un ápex visible, como factores de riesgo, mientras que: el consumo de alimentos preservados y enlatados constituyó un factor de protección. En conclusión, el diagnóstico de MChC tiene una alta frecuencia en individuos seropositivos del estado Barinas y la prevención del desarrollo de insuficiencia cardíaca debe basarse en la atención médica precoz y en medidas educativas para controlar los factores de riesgo.

This study evaluates the risk factors associated with the diagnosis of chronic chagasic miocardiopathy (CChM) in 115 seropositive individuals to anti-Trypanosoma cruzi antibodies, in Barinas state, Venezuela. Serology was performed with ELISA and MABA; while the CChM diagnosis was established by electrocardiography and echocardiography. A complete clinical history including epidemiological, personal/familiar antecedents and psychobiological habits, plus socioeconomic, psychosocial and alimentary habits interviews were performed for each individual. Risk factors were determined through binary logistic regression. Results showed that 81 patients (70,4%; CI95% = 66.4-74.4) had criteria for CChM, of which 74 (64.4%; IC95% = 60.2-68.6) were in phase II; while 34 (29.6%; IC95% = 25.5-33.5) were in phase I of the disease and 7 (6.1%; IC95% = 4.0-8.2) in phase III. In a one year period, two patients in phase III died of heart failure. The diagnosis of CChM was associated with hunting practice, maternal history of cardiopathies, chewing chimó, medical history of hypertension and apex beat visible; it was negatively associated with canned and preserved foods ingest. In conclusion the CChM diagnosis has high frequency in seropositive individuals in Barinas and heart failure prevention must be based on an early medical attention and educative strategies in order to control risk factors.