Determinación de la expresión de cicloxigenasa-2 en el colon de la rata / Determination of cyclooxigenase-2 expression on rat's colon

No disponible

Cyclooxygenase-2 inhibition in colon experimental carcinogenesis.

BACKGROUND: An overexpression of cyclooxygenase-2 (COX-2) has been seen in colon tumors; therefore, COX-2 specific inhibitors may be used as preventive agents. The aim of this study was to investigate the effect of both selective and non-selective COX-2 inhibitors on the incidence of colonic tumors in a model of chemical carcinogenesis in the rat. DESIGN: Experimental study with 65 male Sprague-Dawley rats randomly assigned to one of four groups: (a) control (n = 20), with chemical carcinogenesis using 1-2 dimethylhydrazine (1-2 DMH); (b) acetylsalicylic acid (ASA) (n = 15), with chemical carcinogenesis and the addition of ASA at 30 mg/kg; (c) low-dose rofecoxib (n = 15), with chemical carcinogenesis and the addition of rofecoxib at a dose of 1.2 mg/kg; (d) high-dose rofecoxib (n = 15), with carcinogenesis and the addition of rofecoxib at 3 mg/kg. Carcinogenic induction was performed with 1-2 DMH at a weekly dose of 25 mg/kg for 18 weeks. The main parameter evaluated was percentage of neoplastic colonic tissue, which relates tumor surface area to colon surface area. RESULTS: Rofecoxib at a dose of 3 mg/kg significantly reduced chemical colon carcinogenesis in rats (p < 0.01). Rofecoxib in lower doses had the same effect on adenomas (p < 0.05) with no effect on adenocarcinomas. Rofecoxib reduced COX-2 expression in tumoral tissue from adenomas and adenocarcinomas (p < 0.01). CONCLUSIONS: Rofecoxib prevents chemical colon carcinogenesis in the rat, with a reduction of tumoral colonic percentage in adenocarcinomas and tumoral COX-2 expression.

Inhibición de la ciclooxigenasa-2 en la carcinogénesis cólica experimental / Cyclooxygenase-2 inhibition in colon experimental carcinogenesis

Introducción: se ha comprobado a nivel clínico y experimentalla existencia de sobreexpresión de la ciclooxigenasa-2 (COX-2)en los tumores de colon, por lo que los inhibidores de dicha enzimapodrían tener un efecto preventivo. El objetivo del estudio esinvestigar el efecto de la inhibición de la ciclooxigenasa en un modelode carcinogénesis cólica farmacológica en la rata.Material y métodos: estudio experimental en 65 ratas Sprague-Dawley macho, asignadas a uno de los grupos: control (n =20), con carcinogénesis farmacológica con 1-2 dimetilhidrazina;grupo ácido acetilsalicílico (n = 15), con carcinogénesis y adiciónde AAS, grupo Inhibidores COX-2 a bajas dosis (n = 15), con carcinogénesisy adición de rofecoxib a dosis de 1,2 mg/kg, y grupoInhibidores COX-2 a altas dosis (n = 15), con carcinogénesis y rofecoxiba dosis de 3 mg/kg. El principal parámetro evaluado es elporcentaje de tejido cólico neoplásico y la expresión de COX-2 enel colon normal y neoplásico.Resultados: el rofecoxib a dosis altas reduce el porcentaje decolon ocupado por adenocarcinomas inducidos (p < 0,01). El rofecoxiba dosis bajas presentó el mismo efecto sobre los adenomas(p < 0,05), sin efecto sobre los adenocarcinomas. La expresiónCOX-2 es superior en los adenocarcinomas frente a losadenomas. El rofecoxib redujo la expresión COX-2 respecto alcontrol y AAS (p < 0,01), tanto en los adenomas como en losadenocarcinomas, no mostrando este efecto sobre el colon normal.Conclusiones: el rofecoxib redujo la carcinogénesis cólica inducidaen ratas, reduciendo la expresión COX-2 en los tumores ydisminuyendo el porcentaje de colon neoplásico

Background: an overexpression of cyclooxygenase-2 (COX-2) has been seen in colon tumors; therefore, COX-2 specific inhibitorsmay be used as preventive agents. The aim of this studywas to investigate the effect of both selective and non-selectiveCOX-2 inhibitors on the incidence of colonic tumors in a model ofchemical carcinogenesis in the rat.Design: experimental study with 65 male Sprague-Dawleyrats randomly assigned to one of four groups: (a) control (n = 20),with chemical carcinogenesis using 1-2 dimethylhydrazine (1-2DMH); (b) acetylsalicylic acid (ASA) (n = 15), with chemical carcinogenesisand the addition of ASA at 30 mg/kg; (c) low-dose rofecoxib(n = 15), with chemical carcinogenesis and the addition ofrofecoxib at a dose of 1.2 mg/kg; (d) high-dose rofecoxib (n = 15),with carcinogenesis and the addition of rofecoxib at 3 mg/kg.Carcinogenic induction was performed with 1-2 DMH at a weeklydose of 25 mg/kg for 18 weeks. The main parameter evaluatedwas percentage of neoplastic colonic tissue, which relates tumorsurface area to colon surface area.Results: rofecoxib at a dose of 3 mg/kg significantly reducedchemical colon carcinogenesis in rats (p < 0.01). Rofecoxibin lower doses had the same effect on adenomas (p < 0.05)with no effect on adenocarcinomas. Rofecoxib reduced COX-2expression in tumoral tissue from adenomas and adenocarcinomas(p < 0.01).Conclusions: rofecoxib prevents chemical colon carcinogenesisin the rat, with a reduction of tumoral colonic percentage inadenocarcinomas and tumoral COX-2 expression

Effect of rofecoxib on colon chemical carcinogenesis at colonic anastomotic area in the rat.

AIM: To investigate the effect of the selective cyclooxygenase-2 (COX-2) inhibitor rofecoxib on the incidence of perianastomotic colonic tumors in a model of chemical carcinogenesis in the rat. EXPERIMENTAL DESIGN: Experimental study with 45 male Sprague-Dawley rats randomly assigned to one of three groups: control (n = 15) with colocolic anastomosis and chemical carcinogenesis with 1-2 dimethylhydrazine (1-2 DMH); rofecoxib 0.0027% (n = 15) with colonic anastomosis, chemical carcinogenesis and the addition of dietary rofecoxib at doses of 27 parts per million (ppm), and rofecoxib 0.0058% (n = 15) with colonic anastomosis, chemical carcinogenesis and the addition of dietary rofecoxib at doses of 58 ppm. Carcinogenic induction was performed with 1-2 DMH at a weekly dose of 25 mg/kg of weight for 18 weeks, and colonic tumors induced were analyzed in postoperative week 20. The main parameter evaluated was the percentage of colonic neoplastic tissue, which relates tumor surface area to the colon's surface area. RESULTS: Rofecoxib at doses of 2.5 mg/kg or 0.0058 ppm significantly reduced chemical colon carcinogenesis in rats, both in the perianastomotic area and the rest of the colon (p < 0.01). In the extra-anastomotic area, rofecoxib at doses of 2.5 mg/kg has significantly greater inhibitory effect than rofecoxib in doses of 1.2 mg/kg or 0.0027 ppm (p < 0.005). CONCLUSIONS: Rofecoxib causes a reduction in chemical colon carcinogenesis in rats. This effect is sustained in the perianastomotic area, and the investigation of its role in operated colorectal cancer with risk of locoregional recurrence may therefore be of interest.

Influencia del rofecoxib en la carcinogénesis cólica perianastomótica inducida en ratas / Effect of rofecoxib on colon chemical carcinogenesis at colonic anastomotic area in the rat

Objetivo: investigar el efecto de un inhibidor selectivo de la ciclooxigenasa-2, rofecoxib, en la incidencia de tumores cólicos perianastomóticosen un modelo de carcinogénesis farmacológicaen ratas.Diseño experimental: estudio experimental con 45 ratasSprague-Dawley macho, asignadas aleatoriamente a uno de lostres grupos: control (n = 15), con anastomosis colo-cólica y carcinogénesiscon 1-2 dimetilhidracina; rofecoxib 0,0027% (n = 15),con anastomosis cólica y carcinogénesis farmacológica y adiciónde rofecoxib en la dieta a dosis de 27 partes por millón, y rofecoxib0,0058% (n = 15), con anastomosis, carcinogénesis y adiciónde rofecoxib en la dieta a dosis de 58 ppm. La inducción carcinogénicase realizó con 1-2 DMH a dosis semanal de 25 mg/kg depeso durante 18 semanas y se analizaron los tumores cólicos inducidosen la semana 20 del postoperatorio. El principal parámetroevaluado fue el porcentaje de tejido cólico neoplásico, que relacionala superficie tumoral con la superficie del colon.Resultados: el rofecoxib a dosis de 0,0058 ppm redujo significativamentela carcinogénesis cólica inducida en ratas, tanto a nivelperianastomótico como en el resto del colon (p < 0,01). A nivelextraanastomótico, el rofecoxib a dosis de 2,5 mg/kg fuesignificativamente superior en su efecto inhibidor al rofecoxib adosis de 1,2 mg/kg o 0,0027 ppm (p < 0,005).Conclusiones: el rofecoxib produce una disminución en lacarcinogénesis cólica farmacológicamente inducida en ratas. Esteefecto se mantiene en el área perianastomótica, por lo que puedeser interesante investigar su implicación en el cáncer colorrectalintervenido con riesgo de recidiva locorregional

Aim: to investigate the effect of the selective cyclooxygenase-2(COX-2) inhibitor rofecoxib on the incidence of perianastomoticcolonic tumors in a model of chemical carcinogenesis in the rat.Experimental design: experimental study with 45 maleSprague-Dawley rats randomly assigned to one of three groups:control (n = 15) with colocolic anastomosis and chemical carcinogenesiswith 1-2 dimethylhydrazine (1-2 DMH); rofecoxib0.0027% (n = 15) with colonic anastomosis, chemical carcinogenesisand the addition of dietary rofecoxib at doses of 27 parts permillion (ppm), and rofecoxib 0.0058% (n = 15) with colonic anastomosis,chemical carcinogenesis and the addition of dietary rofecoxibat doses of 58 ppm. Carcinogenic induction was performedwith 1-2 DMH at a weekly dose of 25 mg/kg of weight for 18 weeks,and colonic tumors induced were analyzed in postoperativeweek 20. The main parameter evaluated was the percentage ofcolonic neoplastic tissue, which relates tumor surface area to thecolon’s surface area.Results: rofecoxib at doses of 2.5 mg/kg or 0.0058 ppm significantlyreduced chemical colon carcinogenesis in rats, both inthe perianastomotic area and the rest of the colon (p < 0.01). In the extra-anastomotic area, rofecoxib at doses of 2.5 mg/kg has significantly greater inhibitory effect than rofecoxib in doses of 1.2 mg/kg or 0.0027 ppm (p < 0.005).Conclusions: rofecoxib causes a reduction in chemical coloncarcinogenesis in rats. This effect is sustained in the perianastomoticarea, and the investigation of its role in operated colorectalcancer with risk of locoregional recurrence may therefore be of interest

Influence of rofecoxib on experimental colonic carcinogenesis in rats.

AIM: To investigate the effect of a selective cyclooxigenase-2 (COX-2) inhibitor, rofecoxib, in the prevalence of experimental colon tumors in rats. EXPERIMENTAL DESIGN: Experimental study with 35 male Sprague-Dawley rats, divided into four groups: a) control group without experimental manipulation (n = 5); b) pharmacological carcinogenesis with 1-2 dimethylhydrazine dihydrocloride (n = 10); c) pharmacological carcinogenesis and addition of acetylsalicylic acid (AAS) (n = 10); and d) carcinogenesis and addition of rofecoxib (n = 10). Carcinogenesis was induced with 1-2 dimethylhydrazine at a weekly dose of 25 mg/kg for 18 weeks. Colon tumors were isolated at 20 weeks. Antiinflammatory agents were given at a dose of AAS 30 mg/kg and rofecoxib at 3 mg/kg. RESULTS: The percentage of colonic tumors was significantly reduced in the rofecoxib group. This result was found for all tumors and for the malignant lesions, adenocarcinomas. CONCLUSIONS: Rofecoxib, a selective COX-2 inhibitor, reduced the percentage of drug-induced neoplastic glandular tissue in rats.

Influence of the surgical manipulation of the colon in colonic induced carcinogenesis in rats.

AIM: to investigate the influence of different experimental manipulations in a model of colonic experimental carcinogenesis with pharmacological induction in the rat. EXPERIMENTAL DESIGN: a total of 90 Sprague-Dawley male rats, divided into three groups, were used: non-surgical (n = 30); surgical with colonic trauma (n = 20), and surgical with colo-colonic anastomosis (n = 40). Carcinogenic induction was carried out with 1-2 dimethylhydrazine dihydrochloride. Colonic adenocarcinomas were identified and the number of tumors, as well as tumoral surface and percentage of tumoral surface was established. One-way ANOVA and Chi-square were employed for the statistical analysis. RESULTS: the number of tumors was greater in the surgical group than in the control group, and tumors preferentially developed around the manipulated colon. Surface and tumoral percentage were greater in the surgical group than in the control group, being also greater in the anastomosis group than in the group with colonic trauma. Within anastomosis groups, a greater tumor surface and percentage was found in the group with titanium than in the group with reabsorbable material. CONCLUSIONS: the experimental manipulation of the colon in rats enhances drug-induced colon carcingenesis. The creation of an anastomosis further increases the carcinogenic process compared with simulated anastomosis. This process is also enhanced by the quantity of suture material included in the anastomosis, and by the non-reabsorbable nature of the materials used in the anastomotic line.

Psoriasis pustulosa anular / Annular pustular psoriasis

No disponible

Carcinoma vesical de células pequeñas. Aportación de un nuevo caso y revisión de la literatura / Small cell carcinoma of the bladder. Report of a new case and review of the literature

El carcinoma vesical de células pequeñas representa menos del 1 per cent de los tumores vesicales. Sus características clínicas y epidemiológicas son similares a las del carcinoma transicional. Sin embargo, presenta una mayor agresividad con una elevada tendencia a la infiltración muscular y a la diseminación a distancia. Estos factores y la baja supervivencia observada en estos tumores han motivado la aplicación de esquemas terapéuticos similares a los empleados en el carcinoma pulmonar de células pequeñas. Con la quimioterapia sistémica como eje del tratamiento se han conseguido los mejores resultados no sólo en cuanto a supervivencia sino también en cuanto a preservación vesical, jugando la cistectomía radical un papel de rescate en caso de persistencia local de la enfermedad. Presentamos un nuevo caso de carcinoma vesical de células pequeñas y revisamos la literatura con especial énfasis en las mejores opciones terapéuticas de estos tumores (AU)

No disponible

Experimental model for the study of perianastomotic recurrence in colorectal cancer.

OBJECTIVE: To determine if an experimental model is valid for the study of perianastomotic recurrence in colorectal cancer, comparing it with previous experimental models. METHODS: Experimental study with 40 male Sprague-Dawley rats, assigned to one of the study groups: control group (n = 20), with manipulation of large descending bowel, and colonic anastomosis group (n = 20), with colonic section and colocolic anastomosis. After pharmacological carcinogenesis with 1-2 dimethylhydrazine at a weekly dose of 25 mg/kg for 18 weeks, colonic tumours were studied at the 20th postoperative week. RESULTS: Number of tumours, colic tumoral area and percentage of colic tumoral area were greater in the colonic anastomosis group. In this group with colonic anastomosis all determinations were higher at the perianastomotic large bowel. CONCLUSIONS: We think this experimental model may be the best model to study perianastomotic recurrence in large bowel cancer. The high incidence of induced colic tumours and their location at the perianastomotic area offer a good field to determine response to experimental manipulations on colorrectal cancer.

Modelo experimental para el estudio de la recidiva locorregional del cáncer colorrectal / Experimental model for the study of perianastomotic recurrence in colorectal cancer

Objetivo: evaluar el modelo experimental diseñado mediante comparación con los modelos existentes e investigar si es adecuado para el estudio de la recidiva locorregional del cáncer colorrectal.Métodos: estudio experimental con 40 ratas Sprague-Dawley macho, asignadas aleatoriamente a uno de los dos grupos: control (n=20), con manipulación del colon descendente; y anastomosis cólica (n=20), con sección del colon descendente y posterior anastomosis. Tras inducción carcinogénica con 1-2 dimetilhidrazina a dosis semanal de 25 mg/kg de peso durante 18 semanas, se analizaron los tumores cólicos inducidos en la semana 20 del postoperatorio. Resultados: el número de tumores, la superficie tumoral cólica y el porcentaje de tejido tumoral cólico fueron muy superiores en el grupo con anastomosis cólica frente al grupo control. En los grupos con sutura cólica dichos parámetros fueron muy superiores en el colon perianastomótico respecto al resto del colon. Conclusiones: dada la elevada incidencia de tumores inducidos y su agrupación alrededor del área perianastomótica, creemos que es un modelo experimental ideal para realizar estudios sobre la recidiva locorregional del cáncer colorrectal (AU)

[Small cell carcinoma of the bladder. Report of a new case and review of the literature]. / Carcinoma vesical de células pequeñas. Aportación de un nuevo caso y revisión de la literatura.

Small cell carcinoma of the bladder is a rare entity occurring in fewer than 1% of all the primary bladder tumors. Its clinic and epidemiologyc characteristics are similar to the transitional cell carcinoma. But, its more aggressive with a high tendency to infiltrate the muscular layer and to metastasize. Thus, therapeutic approach used by the pulmonary form has been applied to the bladder carcinoma. The best results has been achieved using systemic chemotherapy, not only in survival rates but in preserving the bladder integrity, playing the radical cystectomy a rescue role in cases of recurrence or persistence of the tumor. We report a new case of small cell carcinoma of the bladder and review the literature with special attention to the different therapeutic approaches.

Perianastomotic colonic tumors after inclusion of titanium or Lactomer in the anastomotic suture line. An experimental study in rats.

OBJECTIVE: The aim of the study was to find out if there are differences in the incidence of colonic tumors at the anastomosis after the inclusion of titanium or the absorbable material Lactomer in the anastomotic suture line. METHODS: Experimental study with 30 male Sprague-Dawley rats, assigned to 1 of 3 study groups: control (colonic anastomosis with interrupted suture); inclusion of titanium (8 mg) in the anastomotic suture line; and inclusion of Lactomer (8 mg) in the anastomotic line. After pharmacological carcinogenesis with 1-2 dimethylhydrazine, perianastomotic tumors were studied in the 20th postoperative week. RESULTS: The inclusion of titanium in the anastomotic line led to more tumors, a larger anastomotic tumoral area and a larger percentage of tumoral area than Lactomer (p < 0.05). The inclusion of Lactomer may have a protective effect against the induction of cancer in the anastomotic area. CONCLUSIONS: Titanium, a material used in mechanical instruments for digestive tract anastomoses, is not an innocuous material. Its presence in the anastomotic line can promote colonic carcinogenesis after induction. The use of mechanical staplers for colonic anastomoses should be relegated to difficult anastomoses that cannot be sewn manually.

Tumores cólicos perianastomóticos tras inclusión de titanio y Lactomer en la línea anastomótica. Un estudio experimental en ratas / Perianastomotic colonic tumors after inclusion of titanium or Lactomer in the anastomotic suture line. An experimental study in rats

OBJETIVO: averiguar si existen diferencias en la incidencia de tumores cólicos anastomóticos tras la inclusión de titanio y de un material reabsorbible (Lactomer) en la línea anastomótica. DISEÑO EXPERIMENTAL: se realizó un estudio experimental empleando 30 ratas Sprague-Dawley macho. Los animales fueron asignados aleatoriamente a uno de los tres grupos de estudio: control (anastomosis cólica con sutura discontínua); inclusión de titanio (8 mg) en la anastomosis realizada con sutura discontínua; e inclusión de Lactomer (8 mg) en las mismas condiciones que para el titanio. Tras inducción carcinogénica farmacológica con 1-2 dimetilhidrazina iniciada en el 8º día del postoperatorio a dosis de 25 mg/kg de peso durante 18 semanas, se estudiaron los tumores perianastomóticos en la semana 20 del postoperatorio. RESULTADOS: la inclusión de titanio en la línea anastomótica indujo mayor número de tumores, superficie tumoral anastomótica y porcentaje de superficie tumoral que el Lactomer (p < 0,05). La inclusión de Lactomer, material reabsorbible parece tener un efecto protector frente a la inducción carcinogenética en el área perianastomótica. CONCLUSIONES: el titanio, material empleado en los instrumentos mecánicos de autosutura para las anastomosis digestivas, no es un material inocuo. Su permanencia en la línea anastomótica puede producir un efecto promotor en la carcinogénesis cólica tras una inducción carcinogenética. El uso de las grapadoras mecánicas para las anastomosis colocólicas debería quedar relegada para aquellas anastomosis difíciles que no pueden realizarse manualmente (AU)

[Asymptomatic renal carcinoma diagnosed based on synchronous metastasis in the thyroid gland]. / Carcinoma renal asintomático diagnosticado a partir de una metástasis sincrónica en tiroides.

Secondary tumors of the thyroid are very rare, being the kidney the most frequent place of the primary tumor. The majority of these metastases appear months or years after the primary renal tumor. We report the case of an asymptomatic renal carcinoma discovered after the histological analysis of a thyroidectomy piece. The treatment of the primary renal tumor was radical nephrectomy. Three years after diagnosis and treatment the patient is free of relapse.

[A case of non Hodgkin Lymphoma in a patient with hepatic cirrhosis by the hepatitis C virus]. / Un caso de linfoma no hodgkiniano en una paciente con cirrosis hepática por el virus de la hepatitis C.

We present a case of non-Hodgkin's lymphoma of B cells in a patient with cirrhosis by hepatitis C virus. Our patient presented scarce symptomatology related with non-Hodgkin's lymphoma. A notable hyperbilirrubinaemia with hypoalbuminaemia were the only features that allowed us to suspect the diagnosis. The diagnostic was proved by necroscopic study. There are several factors involved in the etiology of non-Hodgkin's lymphoma, including infectious agents. Recent Italian studies have suggested an association between C virus infection and non-Hodgkin's lymphoma. We have carried out a bibliographical revision of this association to conclude that important geographical differencies must be pointed out.