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La valoración de citotoxicidad in vitro sobre líneas celulares derivadas de tumores humanos permite explorar la actividad biológica de productos aislados de diferentes fuentes como primer tamizaje en búsqueda de moléculas con potencial actividad anticancerígena. En este trabajo se implementó el método de reducción de resazurina como indicador indirecto de supervivencia celular. Para ello fue necesario seleccionar la concentración de resazurina y el tiempo de incubación ideal para obtener unidades relativas de fluorescencia (URF) óptimas sobre las líneas celulares MCF-7, MKN-45, SiHa, HEp-2, HT-29 y HeLa. Seguidamente, se compararon los resultados de supervivencia obtenidos al emplear el método de reducción MTT y el método de tinción SRB, definidos como ensayos de tipo terminal, con el uso de resazurina, descrita como poco tóxica para las células. La comparación de los métodos se hizo en términos de porcentaje de supervivencia, donde se evaluó la sensibilidad de las líneas a doxorrubicina HCl, un medicamento empleando en el tratamiento del cáncer. Los resultados obtenidos demuestran que el método de reducción de resazurina empleado en una concentración 4,4 µM es útil en ensayos de rutina para detectar cambios significativos de la población celular cuando su crecimiento varía como consecuencia de la exposición a moléculas con actividad citotóxica.Assessment of in vitro cytotoxicity as a model to explore biological activity of compounds isolated from different sources is the first approached to search molecules with potential anticancer activity. This paper is about how to implement resazurin reduction method as an indirect indicator of cell survival. Indeed both optimal resazurin concentration and incubation time were selected on MCF-7, MKN-45, SiHa, HEp-2, HT-29 and HeLa. Next, we compared survival results by using reduction method MTT and staining method SRB defined as end-point tests, and resazurin method described as slightly toxic to cells. The comparison of the methods was done in terms of survival rate to evaluate the sensitivity of the lines to doxorubicin HCl, a medicine used in cancer. The methods were compared in terms of percentage survival by evaluating cell line sensitivity to doxorubicin HCl (a drug used in cancer treatment). The results show that resazurin reduction method used in 4.4 μM is applicable to detect significant changes in cell population exposed to cytotoxic molecules in routine testing.

Se realizó un estudio comparativo de los métodos de resazurina y MTT como indicadores de medida indirecta de sobrevivencia celular, aplicables para la estimación de actividad citotóxica, con el fin de establecer la idoneidad de cada uno de los dos sistemas de detección, a través de la valoración de citotoxicidad sobre tres líneas celulares derivadas de tumores humanos: HEp-2, HT-29 y HeLa, evaluando tres compuestos sintéticos durante un periodo de tratamiento de 48 horas, usando como referencia de actividad Doxorrubicina HCl, un agente antineoplásico. Los resultados obtenidos por los dos métodos revelaron comportamientos semejantes en las condiciones estudiadas en las líneas celulares.A study was carried comparing the resazurina and MTT methods as indicators of indirect measure of cellular survival applied to valuated cytotoxic activity in order to assess the suitability of each of the two detection systems. The comparison was made through the valuation of cytotoxicity on three cell lines derived from human tumors: HEp-2, HT-29 and HeLa, evaluating three synthetic compounds during a treatment period of 48 hours using as a reference activity Doxorubicin HCl. The results obtained by the two methods showed a similar performance under the conditions tested in cell lines.

En la estimación de la posible citotoxicidad de extractos o compuestos en proceso de prospección se emplean métodos de tinción celular como aproximación indirecta para la medición masa celular viable. En ensayos de citotoxicidad sobre las líneas celulares SiHa, MCF-7 y MKN-45 se comparan el método de tinción sulforoda-mina B (SRB), que es un ensayo de tipo terminal, con el uso de resazurina propuesta como poco tóxica para las células. La comparación de los métodos se hizo en términos de porcentaje de supervivencia donde se evaluó la sensibilidad de las líneas a tres compuestos sintéticos durante un periodo de tratamiento de 48 horas usando como referencia de actividad doxorrubicina HCl, un medicamento empleando en cáncer. Los datos obtenidos en los dos tipos de ensayos sometidos a una prueba de correlación mostraron que no hay diferencias significati-vas en ambos métodos permitiendo la comparación entre estos bajo las condiciones usadas. Palabras clave: citotoxicidad, correlación, resazurina, sulforodamina B. Abstract Cell staining methods are commonly used for estimating extracts or compounds’ potential cytotoxic activity when prospecting for indirect quantitative measurement of cell growth and viability. This work compared the sulphorhodamine B (SRB) staining method, which is a terminal cell density measuring assay, and the resazurin method, a cell proliferation assay which is supposed to be less toxic for the cell. The methods were compared in terms of percentage survival by evaluating MCF-7, MKN-45 and SiHa cell line sensitivity to three synthetic compounds using a 48-hour treatment period and doxorubicin HCl (a drug used in cancer treatment) as reference activity. A correlation test using the data obtained from the assays showed that there was no significant difference between the methods in the conditions used here. Key words: cytotoxicity, correlation, sulphorhodamine B assay, resazurin assay.

Para establecer la acción anticancerígena se han propuesto numerosas metodologías, principalmente enfocadas en la valoración de la citotoxicidad in vitro sobre líneas celulares neoplásicas derivadas de diferentes tipos de cáncer humano; sin embargo, gran parte de estas líneas celulares presentan el inconveniente de ser limitadas metabólicamente y, por lo tanto, pueden no resultar apropiadas para establecer la citotoxicidad de potenciales profármacos, al mostrar falsos negativos. La línea celular Hep-G2 se emplea en la detección de moléculas que requieran activación metabólica para ejercer una actividad biológica, por ser de origen hepático y por exhibir actividad de varias enzimas de la fase I y II, que juegan un importante rol en la activación y detoxificación de xenobióticos. Hep-G2 es utilizada como modelo para encontrar actividad citotóxica producida por 2-amino-1-metil-6-fenilimidazol[4,5-b]piridina (PhIP) y ciclofosfamida, en presencia o ausencia de agentes inductores. Para este análisis se mide indirectamente el número de células viables mediante los ensayos de reducción del MTT y de tinción con resazurina. Adicionalmente se evalúa la posibilidad de emplear sistemas de co-cultivos con otras líneas celulares para fortalecer la sensibilidad del método. Se observa una limitada citotoxicidad de PhIP y ciclofosfamida, por lo cual se establece un sistema de cocultivos, en donde las respuestas son similares a las obtenidas con cada línea celular independiente. Los resultados permiten proponer que Hep-G2, pretratada con algunos agentes inductores, muestra, aunque limitadamente, una sensibilidad por PhIP, similar a lo propuesto por diferentes autores.Several methodologies have been proposed in order to establish anticancer action, mainly focused on in vitro cytotoxicity valuation on neoplasic cell lines derived from human cancer. However, most of these cell lines are metabolically incompetent, restricting model sensibility and generating false negative answers. Hep-G2 cell line is widely used because of its high sensibility reflecting phase I and II activity of some enzymes of phase I and II, which play an important role in activation and detoxification of xenobiotics. In this study, Hep-G2 is used as a model to find cytotoxic activity produced by 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) and Cyclophosphamide, in presence or absence of inductor agents. This analysis was carried out by measuring indirectly viable number of cells with assays like MTT and resazurine staining. In addition, the possibility of co-cultures with other cell lines was evaluated according to strengthen method sensibility. Cytotoxicity of PhIP and cyclophosphamide was observed with the cellular staining methods. For this reason a co-culture system was established. The answer was similar to independent cell lines. These results propose that pre-treated Hep-G2 cells with some inductive agents show sensibility by PhIP as different authors postulate.

Assessment of in vitro cytotoxicity as a model to explore biological activity of compounds isolated from different sources is the first approached to search molecules with potential anticancer activity. This paper is about how to implement resazurin reduction method as an indirect indicator of cell survival. Indeed both optimal resazurin concentration and incubation time were selected on MCF-7, MKN-45, SiHa, HEp-2, HT-29 and HeLa. Next, we compared survival results by using reduction method MTT and staining method SRB defined as end-point tests, and resazurin method described as slightly toxic to cells. The comparison of the methods was done in terms of survival rate to evaluate the sensitivity of the lines to doxorubicin HCl, a medicine used in cancer. The methods were compared in terms of percentage survival by evaluating cell line sensitivity to doxorubicin HCl (a drug used in cancer treatment). The results show that resazurin reduction method used in 4.4 μM is applicable to detect significant changes in cell population exposed to cytotoxic molecules in routine testing.

A study was carried comparing the resazurina and MTT methods as indicators of indirect measure of cellular survival applied to valuated cytotoxic activity in order to assess the suitability of each of the two detection systems. The comparison was made through the valuation of cytotoxicity on three cell lines derived from human tumors: HEp-2, HT-29 and HeLa, evaluating three synthetic compounds during a treatment period of 48 hours using as a reference activity Doxorubicin HCl. The results obtained by the two methods showed a similar performance under the conditions tested in cell lines

En la estimación de la posible citotoxicidad de extractos o compuestos en proceso de prospección se emplean métodos de tinción celular como aproximación indirecta para la medición masa celular viable. En ensayos de citotoxicidad sobre las líneas celulares SiHa, MCF-7 y MKN-45 se comparan el método de tinción sulforoda-mina B (SRB), que es un ensayo de tipo terminal, con el uso de resazurina propuesta como poco tóxica para las células. La comparación de los métodos se hizo en términos de porcentaje de supervivencia donde se evaluó la sensibilidad de las líneas a tres compuestos sintéticos durante un periodo de tratamiento de 48 horas usando como referencia de actividad doxorrubicina HCl, un medicamento empleando en cáncer. Los datos obtenidos en los dos tipos de ensayos sometidos a una prueba de correlación mostraron que no hay diferencias significati-vas en ambos métodos permitiendo la comparación entre estos bajo las condiciones usadas. Palabras clave: citotoxicidad, correlación, resazurina, sulforodamina B. Abstract Cell staining methods are commonly used for estimating extracts or compounds’ potential cytotoxic activity when prospecting for indirect quantitative measurement of cell growth and viability. This work compared the sulphorhodamine B (SRB) staining method, which is a terminal cell density measuring assay, and the resazurin method, a cell proliferation assay which is supposed to be less toxic for the cell. The methods were compared in terms of percentage survival by evaluating MCF-7, MKN-45 and SiHa cell line sensitivity to three synthetic compounds using a 48-hour treatment period and doxorubicin HCl (a drug used in cancer treatment) as reference activity. A correlation test using the data obtained from the assays showed that there was no significant difference between the methods in the conditions used here. Key words: cytotoxicity, correlation, sulphorhodamine B assay, resazurin assay.

Several methodologies have been proposed in order to establish anticancer action, mainly focused on in vitro cytotoxicity valuation on neoplasic cell lines derived from human cancer. However, most of these cell lines are metabolically incompetent, restricting model sensibility and generating false negative answers. Hep-G2 cell line is widely used because of its high sensibility reflecting phase I and II activity of some enzymes of phase I and II, which play an important role in activation and detoxification of xenobiotics. In this study, Hep-G2 is used as a model to find cytotoxic activity produced by 2-amino- 1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) and Cyclophosphamide, in presence or absence of inductor agents. This analysis was carried out by measuring indirectly viable number of cells with assays like MTT and resazurine staining. In addition, the possibility of co-cultures with other cell lines was evaluated according to strengthen method sensibility. Cytotoxicity of PhIP and cyclophosphamide was observed with the cellular staining methods. For this reason a co-culture system was established. The answer was similar to independent cell lines. These results propose that pre-treated Hep-G2 cells with some inductive agents show sensibility by PhIP as different authors postulate.

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Abstract: Amplified Fragment Length Polymorphism (AFLP) analysis was used for characterising 13 native Colombian Clostridium spp strains. The DNA extraction method was optimised and the use of cetyl trimethyl ammonium bromide (CTAB) and sodium chloride (NaCl) was incorporated. All strains could be typed in these conditions. The AFLP profiles obtained were submitted to multivariate analysis and compared with previous pulsed field gel electrophoresis (PFGE) results. The results suggested that the set of native strains could correspond to two new species different to those having been described to date. It is proposed that DNA–DNA hybridisation analysis should be done to produce complementary information for describing the new species. [Copyright &y& Elsevier]

Damage control surgery is based on temporal control of the injury, physiologic recovery and posterior deferred definitive management. This strategy began in the 1980s and became a formal concept in 1993. It has proven to be a strategy that reduces mortality in severely injured trauma patients. Nevertheless, the concept of damage control in non-traumatic abdominal pathology remains controversial. This article aims to gather historical experiences in damage control surgery performed in non-traumatic abdominal emergency pathology patients and present a novel management algorithm. This strategy could be a surgical option to treat hemodynamically unstable patients in catastrophic scenarios such as hemorrhagic and septic shock caused by peritonitis, pancreatitis, acute mesenteric ischemia, among others. Therefore, damage control surgery is light amid better short- and long-term results., Competing Interests: Conflict of interest: The authors declare that they have no conflict of interest., (Copyright © 2021 Colombia Medica.)

The overall incidence of duodenal injuries in severely injured trauma patients is between 0.2 to 0.6% and the overall prevalence in those suffering from abdominal trauma is 3 to 5%. Approximately 80% of these cases are secondary to penetrating trauma, commonly associated with vascular and adjacent organ injuries. Therefore, defining the best surgical treatment algorithm remains controversial. Mild to moderate duodenal trauma is currently managed via primary repair and simple surgical techniques. However, severe injuries have required complex surgical techniques without significant favorable outcomes and a consequential increase in mortality rates. This article aims to delineate the experience in the surgical management of penetrating duodenal injuries via the creation of a practical and effective algorithm that includes basic principles of damage control surgery that sticks to the philosophy of "Less is Better". Surgical management of all penetrating duodenal trauma should always default when possible to primary repair. When confronted with a complex duodenal injury, hemodynamic instability, and/or significant associated injuries, the default should be damage control surgery. Definitive reconstructive surgery should be postponed until the patient has been adequately resuscitated and the diamond of death has been corrected., Competing Interests: Conflict of interest: The authors declare that they have no conflict of interest., (Copyright © 2021 Colombia Medica.)

Hollow viscus injuries represent a significant portion of overall lesions sustained during penetrating trauma. Currently, isolated small or large bowel injuries are commonly managed via primary anastomosis in patients undergoing definitive laparotomy or deferred anastomosis in patients requiring damage control surgery. The traditional surgical dogma of ostomy has proven to be unnecessary and, in many instances, actually increases morbidity. The aim of this article is to delineate the experience obtained in the management of combined hollow viscus injuries of patients suffering from penetrating trauma. We sought out to determine if primary and/or deferred bowel injury repair via anastomosis is the preferred surgical course in patients suffering from combined small and large bowel penetrating injuries. Our experience shows that more than 90% of all combined penetrating bowel injuries can be managed via primary or deferred anastomosis, even in the most severe cases requiring the application of damage control principles. Applying this strategy, the overall need for an ostomy (primary or deferred) could be reduced to less than 10%., (Copyright © 2021 Colombia Medica.)

Background: Damage control surgery (DCS) has emerged as a new option in the management of non-traumatic peritonitis patients to increase survival in critically ill patients. The purpose of this study was to compare DCS with conventional strategy (anastomosis/ostomies in the index laparotomy) for severe non-traumatic peritonitis regarding postoperative complications, ostomy rate, and mortality and to propose a useful algorithm in the clinical practice., Methods: Patients who underwent an urgent laparotomy for non-trauma peritonitis at a single level I trauma center in Colombia between January 2003 and December 2018, were retrospectively included. We compared patients who had DCS management versus definitive initial surgical management (DISM) group. We evaluated clinical outcomes and morbidities among groups., Results: 290 patients were included; 81 patients were treated with DCS and 209 patients underwent DISM. Patients treated with DCS had a worse critical status before surgery with higher SOFA score [median, DCS group: 5 (IQR: 3-8) vs. DISM group: 3 (IQR: 1-6), p < 0.001]. The length of hospital stay and overall mortality rate of DCS group were not significant statistical differences with DISM group. Complications rate related to primary anastomosis or primary ostomy was similar. There is not difference in ostomy rate among groups. At multivariate analysis, SOFA > 6 points and APACHE-II > 20 points correlated with a higher probability of DCS., Conclusion: DCS in severe non-trauma peritonitis patients is feasible and safe as surgical strategy management without increasing mortality, length hospital of stay, or complications. DCS principles might be applied in the non-trauma scenarios without increase the stoma rate.

The liver is the most commonly affected solid organ in cases of abdominal trauma. Management of penetrating liver trauma is a challenge for surgeons but with the introduction of the concept of damage control surgery accompanied by significant technological advancements in radiologic imaging and endovascular techniques, the focus on treatment has changed significantly. The use of immediately accessible computed tomography as an integral tool for trauma evaluations for the precise staging of liver trauma has significantly increased the incidence of conservative non-operative management in hemodynamically stable trauma victims with liver injuries. However, complex liver injuries accompanied by hemodynamic instability are still associated with high mortality rates due to ongoing hemorrhage. The aim of this article is to perform an extensive review of the literature and to propose a management algorithm for hemodynamically unstable patients with penetrating liver injury, via an expert consensus. It is important to establish a multidisciplinary approach towards the management of patients with penetrating liver trauma and hemodynamic instability. The appropriate triage of these patients, the early activation of an institutional massive transfusion protocol, and the early control of hemorrhage are essential landmarks in lowering the overall mortality of these severely injured patients. To fear is to fear the unknown, and with the management algorithm proposed in this manuscript, we aim to shed light on the unknown regarding the management of the patient with a severely injured liver., Competing Interests: Conflict of interest:the authors declare not to have any conflict of interest, (Copyright © 2020 Colombia Medica.)

Background: Paravalvular leak is a frequent and important complication after surgical valvular replacement that can cause heart failure, hemolytic anemia and is associated with poor clinical outcomes. Surgical reoperation has been the standard treatment, but it is associated with high morbidity and mortality. Transcatheter closure is a therapeutic alternative. The aim of the present study is to analyze the feasibility and the short and medium-term outcomes of the transcatheter closure of paravalvular leaks., Methods: Single-centre registry of consecutive patients with post-surgical paravalvular leaks, that underwent transcatheter closure, between January 2006 and December 2016. Efficacy and safety results were analyzed during the procedure and at 6-month follow-up., Results: 21 paravalvular leaks (15 mitral, 5 aortic and 1 tricuspid) were closure during 20 procedures. In the initial echocardiography 91% of the leaks were severe. The most used device was the Amplatzer Vascular Plug III® in 10 procedures (50%). The 3D transesophageal echocardiography was used in 70% of cases. The device was successfully implanted in 95% of cases, a regurgitation reduction ≥ 1 grade was achieved in 95% of the cases, and the clinical success was 79%. Six month survival was 100%; however, 3 cases required valvular surgery (15%)., Conclusions: Transcatheter closure of paravalvular leaks is a feasible and safe procedure with high rates of technical, echocardiographic and clinical success in the short and medium term. It is an adequate therapeutic alternative, mainly in high surgical risk patients and multiples comorbidities., (Copyright: © 2020 Permanyer.)

Cystic Fibrosis is a worldwide distributed hereditary disease. The incidence of the main (p.F508del) and other frequent mutations has been determined in a great number of countries and ethnic groups, but its incidence in most Latin American countries has remained unknown until recently. It is now beginning to be recognized as a frequent cause of infant mortality, and some countries report the incidence of their mutations. Colombia started several years ago a concerted program of molecular study of patients which were clinically diagnosed as probable cystic fibrosis. We screened the whole CFTR (ABCC7) coding sequence in 92 patients from 6 different geographic regions, using conventional PAGE analyses and DGGE followed by sequencing. Additionally, we established the frequency of the p.F508del mutation in 130 unrelated healthy controls. The results of this pilot study in Colombian patients from various ethnic admixture show six main mutations: p.F508del (41.8%), c.1811+1.6kbA>G (6.5%), p.G542X (3.8%), p.S549R (2.2%), p.W1282X (1.1%) and p.R1162X (1.1%). Thirteen other rare mutations, including three novel, were detected, accounting for a total of 63.6% known mutations. There is a great variability between the geographic regions, both in the frequency of the p.F508del mutation and non-p.F508del CF chromosomes. Our results point to a varied origin of the disease genes. These results also show that careful scrutiny of the mutations is needed in each part of Latin America in order to establish priority-screening protocols adapted to each country and region., (Copyright 2003 Wiley-Liss, Inc.)