Thermogenic capacity of human periaortic adipose tissue is transformed by body weight.

The anatomical location of adipose tissue might have direct implications for its functionality and risk of cardiovascular disease. Adipose tissue surrounding blood vessels may be thermogenically more active in specific areas of the body, releasing substances that regulate vascular metabolism. In humans, the phenotypic characteristics of adipose tissue surrounding the aorta and the cardiovascular disease risk that it might entail remain largely unknown. Here, we compared thermogenesis-related molecular features of human periaortic adipose tissue samples with those of subcutaneous adipose tissue, obtained by sternotomy from 42 patients undergoing cardiovascular surgery. To determine the expression of genes related to energy expenditure and the levels of some adipokines, histological examinations, quantitative PCR, and protein expression measurements in adipocyte precursor cells were performed. Periaortic adipocytes were smaller than those from subcutaneous tissue. Moreover, weight gain induced periaortic adipocyte hypertrophy (r = -0.91, p<0.01). Compared to subcutaneous tissue, adiponectin, FABP4, IL-4 and IL-6 was decreased in periaortic adipocytes, whereas FGF21, UCP-1, PGC-1a, CITED1, Omentin and TFAM (Mitochondrial protein) increased. Upon analyzing patients' clinical conditions, it emerged that the levels of PGC-1a both in male (r = -0.48 p<0.04) and female (r = -0.61, p<0.05) and TFAM in male (r = -0.72, p<0.0008) and female (r = -0.86, p<0.002) decreased significantly with progressive weight gain. However, no differences were observed in patients with diabetes mellitus 2 or Hyperlipidemia. Adipocytes surrounding the ascending aorta present markers of major thermogenic activity than those in subcutaneous tissue. Nevertheless, this characteristic might change, due to unfavorable metabolic conditions such as obesity, which is a risk factor for cardiovascular disease.

Functional Characterization of Preadipocytes Derived from Human Periaortic Adipose Tissue.

Adipose tissue can affect the metabolic control of the cardiovascular system, and its anatomic location can affect the vascular function differently. In this study, biochemical and phenotypical characteristics of adipose tissue from periaortic fat were evaluated. Periaortic and subcutaneous adipose tissues were obtained from areas surrounding the ascending aorta and sternotomy incision, respectively. Adipose tissues were collected from patients undergoing myocardial revascularization or mitral valve replacement surgery. Morphological studies with hematoxylin/eosin and immunohistochemical assay were performed in situ to quantify adipokine expression. To analyze adipogenic capacity, adipokine expression, and the levels of thermogenic proteins, adipocyte precursor cells were isolated from periaortic and subcutaneous adipose tissues and induced to differentiation. The precursors of adipocytes from the periaortic tissue accumulated less triglycerides than those from the subcutaneous tissue after differentiation and were smaller than those from subcutaneous adipose tissue. The levels of proteins involved in thermogenesis and energy expenditure increased significantly in periaortic adipose tissue. Additionally, the expression levels of adipokines that affect carbohydrate metabolism, such as FGF21, increased significantly in mature adipocytes induced from periaortic adipose tissue. These results demonstrate that precursors of periaortic adipose tissue in humans may affect cardiovascular events and might serve as a target for preventing vascular diseases.

Caracterización histológica e inmunocitoquímica de la grasa infrapatelar de Hoffa / Histological and immunohistochemical characterization of infrapatellar Hoffa's fat

El presente estudio tuvo como objetivo la caracterización histológica e inmunocitoquímica de la grasa infrapatelar de Hoffa (GIH) en 12 pacientes intervenidos por artroscopia, meningoplastia o remplazo de rodilla. Las fibras elásticas estuvieron presentes en la grasa infrapatelar con distribución unidireccional fascicular, se plantea una relación funcional en la biomecánicas del movimiento articular de la rodilla. Por otra parte las pruebas de inmunocitoquimica arrojaron marcaje positivo para vimentina, marcador de células del tejido conectivo; células mesenquimales y negativo para el resto de los anticuerpos estudiados.

Utilización profiláctica de antibióticos en la unidad médico-quirúrgica de un hospital de la ciudad de Bogotá / Prophylactic use of antibiotics in the medical-chirurgic unit of a Bogotá hospital

Se realizó un estudio descriptivo de corte transversal para evaluar las pautas de profilaxis antimicrobiana en cirugía que se siguen en la Clínica Fundadores (cf) de la ciudad de Bogotá, institución de tercer nivel de atención. La información se obtuvo a partir de fuentes secundarias y se recopiló en un formato diseñado para tal fin. Se seleccionaron 214 procedimientos en un período de dos meses, sin diagnóstico infeccioso previo o que no se les había prescrito antibióticos con fines terapéuticos antes de la cirugía. La evaluación se desarrolló sobre la base de un algoritmo que explica si las variables indicación profiláctica, agente antimicrobiano, dosis, momento de administración y régimen posoperatorio, están de acuerdo con protocolos nacionales e internacionales previamente seleccionados. Los resultados muestran que se administran antibióticos cuando la profilaxis no estaba recomendada (29,1%) y se prolonga la profilaxis con dosis posoperatorias cuando la recomendación es dosis única (65,2%), lo que evidencia que la tendencia en la clínica consiste en la aplicación de profilaxis excesiva. En menor proporción está el momento de administración inadecuado. Como conclusiones, se puede afirmar que no existe uniformidad de criterios en cuanto a la administración de la antibioticoprofilaxis quirúrgica. Las cirugías que se realizaron con mayor frecuencia en los meses de estudio corresponden a la especialidad gastrointestinal, seguidas de las cirugías de ortopedia y traumatología. La inclinación en el uso de antibióticos profilácticos está orientada a la utilización de cefalosporinas de primera generación seguido de la combinación gentamicina + clindamicina.

A descriptive cross-sectional study was carried-out in order to evaluate patterns of antimicrobial prophylaxis in surgery that they are continued in the Clinica Fundadores (cf) of Bogota city, classified in the third level of attention. The necessary information for the development of the study was obtained starting from secondary sources and it was gathered in a format designed for such purpose. 214 procedures were selected in a period of two months without previously infectious diagnosis and/or without antibiotics prescription for therapeutic reasons before de surgery. The assessment was developed on the basis of an algorithm that explains if the variables: indication prophylaxis, antimicrobial agent, dose, administration moment and postoperative regimen, are agree with previously selected national and international protocols. The results show that in several cases antimicrobial prophylaxis was not applied according with the recommendations of the protocols. Results shows administration of antibiotics when the prevention was not recommended (29.1%) and prolonging the prevention with postoperative dose when the recommendation is unique dose (65.2%), which evidences that the tendency in the clinic consists on the application of excessive prevention. The less proportion of errors are in the administration time. As conclusion, the study can affirm there are no unified criteria about the administration of antimicrobial prophylaxis in surgical procedures. The most frequent surgeries did in such period of time belong to gastrointestinal and traumatology specialties. The prophylaxis is oriented to the utilization of first generation cephalosporines and the combination gentamicin + clindamycin.

Aislamiento e identificación de células madre adultas a partir de la grasa infrapatelar de Hoffa / Isolation and identification of stem cells derived of infrapatelar fat pad

Introducción: La grasa infrapatelar de Hoffa es una inclusión infraarticular presente en la rodilla y existen evidencias que células multipotentes están presentes en tejido adiposo del humano adulto. Objetivo: El propósito de este trabajo es aislar e identificar células mesenquimales a partir de muestras de la grasa de Hoffa tomadas de pacientes a los que se les practicó cirugía de rodilla que expongan este tejido. Metodología: Una vez obtenido el consentimiento informado de un total de 12 pacientes, se obtuvo la muestra de tejido graso. La grasa fue disgregada incubándola en colagenasa en PBS a 37ºC y con agitación, luego se inactivó con suero fetal bovino, se separaron mediante centrifugación los adipocitos maduros de las células multipotentes y se obtuvieron las muestras para sembrar en medio Mesencult. Una porción de muestra fue utilizada para identificación mediante citometría de flujo y otra parte para ser coloreada con azul de metileno. Resultados y Discusión: Tanto en las tinciones con azul de metileno como en los cultivos celulares se han apreciado células con la morfología propia de una célula mesenquimal en forma de estrella y que fueron corroborados mediante citometría de flujo para los marcadores CD13, CD29, CD59 y CD105; igualmente hemos podido observar la efectividad del tratamiento enzimático. Conclusiones: En la actualidad nos encontramos consolidando los cultivos primarios para posteriormente diferenciarlos en líneas celulares específicas que puedan ser utilizadas en estudios de patologías, tales como obesidad, diabetes y trastornos articulares...

Introduction: The infrapatellar fat pad (sometimes know Hoffa's pad) is a soft tissue that lies beneath the patella (kneecap) separating it from the femoral condyle. There is evidence suggesting the presence of stem cells on adipose tissue in the adult human. Objective: The purpose of this work is to isolate and identify grown stem cells from Hoffa's fat samples obtained from patients undergoing surgeries exposing this tissue. Materials and Methods: After obtaining informed consent, the biopsy of Hoff's fat pad was obtained. The samples were incubated with collagenase and PBS a 37ºC and agitated, then it was inactivated with fetal bovine serum and centrifuged, washed twice with PBS, the pellet was resuspended and one part was cultivated on Mesencult medium the other part was used for flow cytometry and stained with methylene blue for morphologic analysis. Also before and after the enzyme digestion, the samples were added to 10% formaldehyde to evaluate the collagenase treatment. Results and analysis: The results show the effectiveness of the enzymatic treatment, the architecture of the adipose tissue was lost. The star shape stem cells morphology was appreciated with methylene blue in the cultures, it was corroborated by flow cytometry with CD13, CD29, CD59 and CD 105 markers. Conclusions: Primary cultures are consolidating, the next aim will be to obtain differentiated specific cell types that can be use in the study of obesity, diabetes and articular illnesses...