A study of the mechanical properties and cytocompatibility of lactide and caprolactone based scaffolds filled with inorganic bioactive particles.

The mechanical properties of highly porous (90% porosity) poly(l-lactide) (PLLA), poly(ε-caprolactone) (PCL) and poly(l-lactide/ε-caprolactone) (PLCL) were investigated. Young's modulus of non-porous PLLA, PCL and PLCL dropped from 2263.4, 183.7 and 5.7 MPa to 16.8, 1.0 and 1.0 MPa, respectively, for their ~90% porous counterparts. Elongation at break of PCL decreased noticeably with porosity fraction while PLCL maintained a highly elastomeric character and strain recovery capacity even in the presence of pores. Inorganic bioactive particles (hydroxyapatite or bioglass) were added to confer bioactivity to the aforementioned synthetic bioresorbable polymers, and their effect on the mechanical properties was also investigated. Addition of 15 vol.% of inorganic bioactive particles increased the Young's modulus of highly porous PLLA from 16.2 to ~30 MPa. On the contrary, the difference between Young's modulus of filled and unfilled PCL and PLCL scaffolds was not statistically significant. Finally, an in vitro study of the cytocompatibility and adhesion of adipose derived stem cells (ADSCs) was conducted. The observed viability and excellent adhesion of these cells to both porous and non-porous templates indicate that the employed materials can be good candidates for application in tissue engineering.

[Biodegradable catheters for fistula prevention in hypospadias. Experimental preliminary study]. / Sondas biodegradables para la prevención de las fístulas de hipospadias. Estudio preliminar experimental.

INTRODUCTION: Continuous technical innovations are not enough to resolve the high incidence of fistula after hypospadias repair. A urethral catheter-tutor made of reabsorbable polymeric biomaterial (RPB) which could be left in situ long enough could reduce the complications. TARGET: To investigate in an animal model differents RPB to be used in urology. METHODOLOGY: CRL Wistar rats, males, divided into 5 equal groups according to the used polymers: polylactide; lactic-coprolactone copolymer; lactic-glycolic copolymer; simulated; control silicones. Three individuals were sacrificed per group at 4th, 10th and 16th week. In all animals (exceptuating the simulated group), biomaterial was fixed to the bladder wall bylaparotomy. Animals remained in individual housing and kept under daily control of hematuria during the first 15 days and weekly weight and urine control for pH and lactate. After being slaughtered, remaining polymer was collected for chemical analysis and bladder tissue for hystologic study. RESULTS: There was no mortality, hematuria nor other clinical signs. The bladder wall showed a mild foreign body reaction. The values of lactate and pH in urine did not reach toxic levels. Lactic-glycolic was totally reabsorbed by the 10th week and had the lowest degree of calcification. Polylactide and lactic-coprolactone remained intact. CONCLUSION: The model of urinary bladder has proven useful for studying the degradation of bioresorbable polymers. The analyzed polymers have spent long time to be reabsorbed, so we will have to study new others.

Sondas biodegradables para la prevención de las fístulas de hipospadias. Estudio preliminar experimental / Biodegradable catheters for fistula prevention in hypospadias. Experimental preliminary study

INTRODUCCIÓN: Las continuas innovaciones técnicas no acaban de solucionar la alta incidencia de fístulas tras la reparación del hipospa-dias. Una sonda-tutor hecha de un biomaterial polimérico reabsorbible (BPR) que pudiera dejarse in situ el tiempo suficiente podría disminuir las complicaciones.Objetivo. Investigar en un modelo animal diferentes BPR para su uso en urología.Material y métodos. Ratas Wistar macho (N= 45) divididas en 5 grupos en función de los polímeros empleados: polilactida; copolímero láctico-coprolactona; copolímero láctico-glicólico; simulado; control de silicona. Se sacrificaron 3 individuos por grupo a las 4, 10 y 16 semanas. A todos los animales (excepto al grupo simulado) se les fijó el material a la pared vesical por laparotomía. Los animales perma-necieron en alojamiento individual, con control diario de hematuria y control semanal de peso y de orina para pH y lactato. Al sacrificio, se recogió el material remanente para estudio químico y tejido vesical para valoración histológica.Resultados. No hubo mortalidad, hematuria ni otros signos clí-nicos. La pared vesical presentó una leve reacción a cuerpo extraño. Los valores de pH y lactato en orina no alcanzaron niveles tóxicos. El láctico-glicólico se reabsorbió totalmente a la 10ª semana y el polilactida y el láctico-coprolactona permanecieron íntegros. El polilactida tuvo alto grado de calcificaciones a partir de la 16ª semana.Conclusiones. Este modelo ha demostrado su utilidad para el es-tudio de la degradación del BPR. Los polímeros estudiados tardan de-masiado tiempo en reabsorberse por lo que habrá que investigar nuevos compuestos

INTRODUCTION: Continuous technical innovations are not enough to resolve the high incidence of fistula after hypospadias repair. A urethral catheter-tutor made of reabsorbable polymeric biomaterial (RPB) which could be left in situ long enough could reduce the complications.Target. To investigate in an animal model differents RPB to be used in urology.Methodology. CRL Wistar rats, males, divided into 5 equal groups according to the used polymers: polylactide; lactic-coprolactone co-polymer; lactic-glycolic copolymer; simulated; control silicones. Three individuals were sacrificed per group at 4th, 10th and 16th week. In all animals (exceptuating the simulated group), biomaterial was fixed to the bladder wall by laparotomy. Animals remained in individual hous-ing and kept under daily control of hematuria during the first 15 days and weekly weight and urine control for pH and lactate. After being slaughtered, remaining polymer was collected for chemical analysis and bladder tissue for hystologic study.Results. There was no mortality, hematuria nor other clinical signs. The bladder wall showed a mild foreign body reaction. The values of lactate and pH in urine did not reach toxic levels. Lactic-glycolic was totally reabsorbed by the 10th week and had the lowest degree of calci-fication. Polylactide and lactic-coprolactone remained intact.Conclusion. The model of urinary bladder has proven useful for studying the degradation of bioresorbable polymers. The analyzed poly-mers have spent long time to be reabsorbed, so we will have to study new others

Estandarización de la cuantificación de la concentración de hierro en el hígado por resonancia magnética / Standardization of the quantification of iron concentration in the liver by magnetic resonance imaging

Objetivo. Calibrar máquinas de RM de 1,5 teslas para la cuantificación de la concentración de hierro en el hígado. Material y métodos. En 28 RM de 1,5 teslas se ha analizado un fantoma con cuatro tubos con diferentes concentraciones de cloruro de hierro III y uno sin hierro, que reproduce a dos pacientes promedio con sobrecarga férrica moderada y alta con las secuencias de un modelo de cuantificación. Se midió para cada tubo la ratio de intensidad de señal con el tubo sin hierro y se calcularon los niveles de concentración teóricos en cada máquina según el modelo para los dos niveles de sobrecarga. Se compararon los resultados con los de la máquina de referencia en la que se habían diseñado el modelo y el fantoma, calculando la diferencia porcentual. Resultados. La diferencia porcentual media de las ratios con respecto a los del centro de referencia fue 11% (0,3-39). La media de los valores de concentración de hierro fue de 71μmol Fe/g para la sobrecarga media, y de 193μmol Fe/g para la sobrecarga alta. La diferencia porcentual media fue del 6% (1,2-37%) y 3,4% (0-16%) respectivamente. En dos máquinas se aplicó un factor de corrección de forma que la diferencia porcentual fue inferior al 25% en todos los casos. Conclusión. Se han calibrado 28 máquinas de 1,5 teslas para la cuantificación de la concentración de hierro en el hígado con una variabilidad menor del 25% (AU)

Objective. To calibrate 1.5 tesla magnetic resonance scanners for the quantification of the concentration of iron in the liver. Material and methods. We analyzed twenty-eight 1.5 tesla magnetic resonance scanners using a phantom with four tubes containing different concentrations of iron (III) chloride and one tube without iron. The phantom represented two typical patients: one with moderate iron overload and one with high iron overload. We measured the signal intensity ratio between each iron-containing tube and the tube without iron; then we calculated the theoretical levels of iron concentration in each scanner according to the model for the two levels of overload. We compared the results of each scanner with those of the reference scanner in which the model and the phantom had been designed, and we calculated the percentage of difference between the two scanners. Results. The mean difference in the ratios compared to the reference center was 11% (0.3-39). The mean concentration of iron was 71μmol Fe/g for moderate overload and 193μmol Fe/g for high overload. The mean difference was 6% (1.2- 7%) and 3.4% (0-16%). respectively. In two scanners, we applied a correction factor so that the difference was below 25% in all cases. Conclusion. We calibrated twenty-eight 1.5 tesla scanners for the concentration of iron in the liver and achieved variability less than 25% (AU)

[Standardization of the quantification of iron concentration in the liver by magnetic resonance imaging]. / Estandarización de la cuantificación de la concentración de hierro en el hígado por resonancia magnética.

OBJECTIVE: To calibrate 1.5 tesla magnetic resonance scanners for the quantification of the concentration of iron in the liver. MATERIAL AND METHODS: We analyzed twenty-eight 1.5 tesla magnetic resonance scanners using a phantom with four tubes containing different concentrations of iron (III) chloride and one tube without iron. The phantom represented two typical patients: one with moderate iron overload and one with high iron overload. We measured the signal intensity ratio between each iron-containing tube and the tube without iron; then we calculated the theoretical levels of iron concentration in each scanner according to the model for the two levels of overload. We compared the results of each scanner with those of the reference scanner in which the model and the phantom had been designed, and we calculated the percentage of difference between the two scanners. RESULTS: The mean difference in the ratios compared to the reference center was 11% (0.3-39). The mean concentration of iron was 71 µmol Fe/g for moderate overload and 193 µmol Fe/g for high overload. The mean difference was 6% (1.2- 7%) and 3.4% (0-16%). respectively. In two scanners, we applied a correction factor so that the difference was below 25% in all cases. CONCLUSION: We calibrated twenty-eight 1.5 tesla scanners for the concentration of iron in the liver and achieved variability less than 25%.

Adaptación en el intestino corto: efecto de la nutrición enteral mínima y los probióticos sobre la proliferación y la apoptosis en la pared intestinal / Adaptation in the small intestine: effect of minimal enteral nutrition and probiotics on proliferation and apoptosis in the intestinal wall

Introducción. La integridad de la pared intestinal es fundamental en la función de la barrera y depende del balance de proliferación/apoptosis. El intestino Corto (IC) o la Nutrición Parenteral (NP) inducen un alto índice de translocación bacteriana (TB) seguramente por fallo dela barrera intestinal. La administración de probióticos o la nutrición enteral mínima(NEM) han reducido la TB en modelos animales. Objetivos. Determinar en 2 modelos animales de TB (IC o NP)el efecto de la NEM y los probióticos sobre los índices de proliferación(IP) y apoptosis (IA) de la pared intestinal. Metodología. Setenta y una ratas Wistar, divididas en 4 grupos: 1)NP (N=23): Nutrición parenteral; 2) NPNEM (N=16): NP + NEM (2,9g/100 g/día dieta estándar); 3) RES (N=15): Resección intestinal 80%y dieta oral estándar; 4) RESPROB (N=17): RES + probióticos (..) (AU)

Background. The intestinal wall integrity is central to the barrier function and depends on the balance of proliferation/apoptosis. Short bowel (SB) or Parenteral Nutrition (PN) induce high bacterial translocation (BT) probably by the intestinal barrier bug. Probiotics or minimal enteral nutrition (MEN) have reduced BT in animal models. Objective. Determine in two BT animal models (SB or PN) the effect of MEN or probiotics on proliferation and apoptosis rates of the intestinal wall. Methods. Seventy-one Wistar rats, divided into 4 groups: 1) PN(N = 23): parenteral nutrition; 2) PNMEN (N = 16): PN + MEN (2.9g/100 g/day standard diet); 3) RES (N = 15): 80% bowel resection (..) (AU)

[Adaptation in the small intestine: Effect of minimal enteral nutrition and probiotics on proliferation and apoptosis in the intestinal wall]. / Adaptación en el intestino corto: efecto de la nutrición enteral mínima y los probióticos sobre la proliferación y la apoptosis en la pared intestinal.

BACKGROUND: The intestinal wall integrity is central to the barrier function and depends on the balance of proliferation/apoptosis. Short bowel (SB) or Parenteral Nutrition (PN) induce high bacterial translocation (BT) probably by the intestinal barrier bug. Probiotics or minimal enteral nutrition (MEN) have reduced BT in animal models. OBJECTIVE: Determine in two BT animal models (SB or PN) the effect of MEN or probiotics on proliferation and apoptosis rates of the intestinal wall. METHODS: Seventy-one Wistar rats, divided into 4 groups: 1) PN (N = 23): parenteral nutrition; 2) PNMEN (N = 16): PN + MEN (2.9 g/100 g/day standard diet); 3) RES (N = 15): 80% bowel resection and standard oral diet; 4) RESPROB (N = 17): RES + probiotics (7 X 10(9) CFU Bifidobacterium lactis). After 10 days in metabolic cages, mesenteryc lymph nodes, portal blood and peripheral blood were cultured. By immunohistochemistry, proliferation and apoptosis index were calculated as well as the proliferation-apoptosis rate. RESULTS: BT: decreased in PNMEN (45%) and RESPROB groups (35%) versus PN (65%) and RES (67%) groups (p<0.05). Proliferation index: was better in PNMEN (12,07) and RESPROB (13,93) groups than PN (7,45) and RES (5,54) groups. (p

[Detection of bacterial translocation by polymerase chain reaction in an experimental short bowel model]. / Diagnóstico de la translocación bacteriana en el intestino corto experimental mediante reacción en cadena de polimerasa.

BACKGROUND: Bacterial overgrowth occuring after massive bowel resection, facilitates Gram-negative intestinal Bacterial Translocation (TB). Probiotic agents might have beneficial effects on TB. On the other hand, polymerase chain-reaction (PCR) has better sensitivity than conventional methods for bacterial detection and has not been investigated in experimental models of short bowel syndrome and TB. OBJECTIVE: To test the hypothesis that the administration of Bifidobacterium lactis (BL) decreases Escherichia coli Bacterial Translocation (ECTB) in experimental short bowel syndrome and to confirm the better sensitivity of PCR technique to detect ECTB. METHODS: Adult Wistar rats, orally fed with standard rat chow and tap water "ad libitum", were maintained in individual metabolic cages for ten days and divided into three groups: Control (n = 15): non-manipulated animals. RES (n = 15): 80% gut resection. Daily administration 1 ml of sterile water, after orogastric intubation. RES-PRO (n = 18): same resection and daily administration of 7.8 x10(9) Bifidobacterium lactis Colony Forming Units (CFU). At the end of the experiment, mesenteric lymph nodes (MLN), and both peripheral and portal blood samples were recovered and cultured by standard procedures. Also, genomic DNA from E. coli was detected by PCR technique. RESULTS: By conventional cultures ECTB was detected in 0% in the control group, 73% in the RES group and 33% in the RES-PRO group. PCR technique detected ECTB in 47% of the control group, 87% of the RES group and 33% of RES-PRO group, showing higher sensitivity. By both methods, animals receiving BL (RES-PRO group) showed less ECTB. By conventional culture, the relative risk (RR) was 0.45 (95% CI 0,22-0,79) and the number needed to treat (NNT) was 3 (95% CI 0-11). By PCR technique, the RR was 0.38 (95% CI 0.19-0.76), and the NNT 2 (95% CI 0-4). CONCLUSIONS: 1) Administration of Bifidobacterium lactis reduces the incidence of ECTB. 2) PCR technique is a more sensitive method for ECTB detection.

[Short bowel syndrome in the research setting: 15 years' experience]. / El síndrome de intestino corto en el ambito experimental: experiencia de 15 años.

The fight against infection and liver disease associated with parenteral nutrition (PN) are surely two of the most problematic aspects in the management of paediatric patients with short bowel syndrome (SBS). In the Research Unit of Donostia Hospital, we have spent the past 15 years investigating different ways of reducing these complications in an experimental model of short bowel in the Wistar rat (resection of 80% of the small bowel, with and without PN). All the experiments had a duration of 10 days and 323 animals reached the end of the study period. Nine groups were established in which some type of intervention was performed, and there were 8 control groups. The interventions were: 3 dietary (minimal enteral nutrition [MEN] with low or high dose probiotics); 5 pharmacological (administration of growth hormone [GH], epidermal growth factor [EGF], insulin, cholecystokinin [CCK], and selective intestinal decontamination [SID]); and 1 surgical (resection of the ileocaecal valve). Infection due to bacterial translocation (BT) was detected by culture of mesenteric lymph nodes, portal blood and peripheral blood, and liver damage by the levels of proinflammatory cytokines (IL-1 and TNF-alpha). In summary, our results are: Probiotics, MEN and SID reduce BT. Liver damage was milder in the groups with MEN, SID and CCK. The groups receiving GH, EGF or insulin presented a higher incidence of BT. BT was lower after resection of the ileocaecal valve. In conclusion, the probiotics, MEN and CCK could be useful in the management of children with SBS. These data confirm the utility of this experimental model of short bowel for the investigation of different aspects of SBS.

Diagnóstico de la translocación bacteriana en el intestino corto experimental mediante reacción en cadena de polimerasa / Detection of bacterial translocation by polymerase chain reaction in an experimental short bowel model

Introducción. El sobrecrecimento bacteriano que ocurre tras la resección intestinal masiva facilita la translocación de gérmenes gramnegativos intestinales. Los probióticos pueden tener efectos beneficiosos sobre la translocación bacteriana (TB).Por otro lado, la reacción en cadena de polimerasa (PCR) tiene más sensibilidad que los métodos convencionales para la detección bacteriana y no ha sido investigada en modelos experimentales de intestino corto y TB. Objetivo. Poner a prueba la hipótesis de que la administración de un probiótico (Bifidobacterium lactis, BL) disminuye la translocación de Escherichia coli en un modelo de intestino corto experimental bajo probióticos y confirmar la mejor sensibilidad de la técnica de PCR para detectar TB. Material y métodos. Cuarenta y ocho ratas wistar adultas alimentadas por vía oral se mantuvieron en cajas metabólicas individualizadas durante diez días y se dividieron en tres grupos:- Control (n=15): animales no manipulados.- RES (n=15): Resección intestinal del 80% y administración diaria de 1 ml de agua por sondaje orogástrico.- RES-PRO (n=18): la misma resección y administración diaria de7,8x109 unidades formadoras de colonias (UFC) de Bifidobacteriumlactis. Al final del experimento se tomaron muestras para cultivo bacteriológico de sangre portal y periférica y de ganglios linfáticos mesentéricos. Además se detectó ADN genómico de E. coli por PCR. Resultados. Por cultivo convencional no se detectó translocación de E. coli en el grupo control. En el grupo RES fue del 73% y en el grupo RES-PRO, del 33%. Por PCR se detectó translocación en el 47% del grupo control, en el 87% del grupo RES, y en el 33% del grupo RESPRO, mostrando así alta sensibilidad. Por ambos métodos, los animales que recibieron BL mostraron menos translocación. Por cultivo convencional, el riesgo relativo (RR)fue de 0,45 (95% CI 0,22-0,79) y el número necesario a tratar (NNT)fue 3 (95% CI 0-11). Por PCR, el RR fue de 0,38 (95% CI 0.19-0.76),y el NNT 2 (95% CI 0-4).Conclusiones. 1) La administración de Bifidobacterium lactis reduce la incidencia de translocación. 2) La técnica de PCR es más sensible para la detección de la translocación por E. coli (AU)

Background. Bacterial overgrowth occurring after massive bowel resection, facilitates Gram-negative intestinal Bacterial Translocation(TB). Probiotic agents might have beneficial effects on TB. On the other hand, polymerase chain-reaction (PCR) has better sensitivity than conventional methods for bacterial detection and has not been investigated in experimental models of short bowel syndrome and TB. Objective. To test the hypothesis that the administration of Bifidobacteriumlactis (BL) decreases Escherichia coli Bacterial Translocation(ECTB) in experimental short bowel syndrome and to confirm the better sensitivity of PCR technique to detect ECTB. Methods: Adult Wistar rats, orally fed with standard rat chow and tap water “ad libitum”, were maintained in individual metabolic cages for ten days and divided into three groups:- Control (n=15): non-manipulated animals.- RES (n=15): 80% gut resection. Daily administration 1 ml of sterile water, after or gastric intubation.- RES-PRO (n=18): same resection and daily administration of7.8x109 Bifidobacterium lactis Colony Forming Units (CFU).At the end of the experiment, mesenteric lymph nodes (MLN), and both peripheral and portal blood samples were recovered and cultured by standard procedures. Also, genomic DNA from E. coli was detected by PCR technique. Results. By conventional cultures ECTB was detected in 0% in the control group, 73% in the RES group and 33% in the RES-PRO group. PCR technique detected ECTB in 47% of the control group, 87% of the RES group and 33% of RES-PRO group, showing higher sensitivity. By both methods, animals receiving BL (RES-PRO group) showed less ECTB. By conventional culture, the relative risk (RR) was 0.45(95% CI 0,22-0,79) and the number needed to treat (NNT) was 3 (95%CI 0-11). By PCR technique, the RR was 0.38 (95% CI 0.19-0.76), and the NNT 2 (95% CI 0-4). Conclusions: 1) Administration of Bifidobacterium lactis reduces the incidence of ECTB. 2) PCR technique is a more sensitive method for ECTB detection (AU)

El síndrome de intestino corto en el ámbito experimental: experiencia de 15 años / Short bowel syndrome in the research setting: 15 year´experience

En el manejo de pacientes pediátricos con síndrome de intestino corto (SIC), la lucha contra la infección y la hepatopatía asociada a la nutrición parenteral (NP), son seguramente algunos de los aspectos más problemáticos. En la Unidad Experimental del Hospital Donostia llevamos investigando durante los últimos 15 años diferentes formas de reducir estas complicaciones en un modelo de intestino corto experimental en la rata Wistar (resección del 80% del intestino delgado con o sin NP). Todos los experimentos duraron 10 días y 323 animales llegaron al final del periodo de estudio. Se diseñaron 9 grupos que recibieron algún tipo de intervención y 8 grupos control. Las intervenciones fueron tres dietéticas (nutrición enteral mínima [NEM] y probióticos a dosis baja y alta), cinco farmacológicas (administración de hormona de crecimiento [GH], factor de crecimiento epidérmico [EGF],insulina, colecistoquinina [CCQ] y descontaminación intestinal selectiva[DIS]) y una quirúrgica (resección de la válvula ileocecal).La infección en forma de translocación bacteriana (TB) se detectó cultivando los ganglios linfáticos mesentéricos, sangre portal y sangre periférica, y el daño hepático, por los niveles de citoquinas proinflamatorias (..) (AU)

The fight against infection and liver disease associated with parenteral nutrition (PN) are surely two of the most problematic aspects in the management of paediatric patients with short bowel syndrome (SBS).In the Research Unit of Donostia Hospital, we have spent the past 15years investigating different ways of reducing these complications in an experimental model of short bowel in the Wistar rat (resection of80% of the small bowel, with and without PN). All the experiments had a duration of 10 days and 323 animals reached the end of the study period. Nine groups were established in which some type of intervention was performed, and there were 8 control groups. The interventions were:3 dietary (minimal enteral nutrition [MEN] with low or high dose probiotics);5 pharmacological (administration of growth hormone [GH],epidermal growth factor (..) (AU)

Minimizing creatine kinase variability in rats for neuromuscular research purposes.

Rat serum or plasma creatine kinase (CK) activity is widely used to evaluate myopathic processes, to test the myotoxicity of different drugs, or to analyse the benefits of emerging gene therapies in some neuromuscular disorders. However, great variability is found in this determination. The aim of this study has been to control some factors of variation in order to reduce variability and increase the reproducibility of analytical data. 8-10-week-old Wistar-Han rats were used. The study consisted of four sequential phases. Phase I aimed to analyse the effect of ether and isoflurane as anaesthetic drugs. The objective of Phase II was to evaluate bleeding rats via retro-orbital sinus vs. tail vein. Phases III and IV were designed as two separate, repeated measure experiments on two factors: habituation to laboratory handling procedures in Phase III and gender in Phase IV. The repeated factor was the storage temperature of blood sample prior to centrifugation. Ether did not significantly increased the CK value. Using isoflurane, getting rats accustomed to laboratory handling procedures and whole blood refrigeration prior to centrifugation and serum separation resulted in statistically significant reduction in CK value and variability. Male rats showed significantly higher values than female rats. In the light of our findings, CK value and variability in rats may be minimized by choosing tail vein as site of bleeding, getting rats accustomed to laboratory handling procedures and maintaining whole blood refrigerated until centrifugation and serum separation.

[Effect of the administration of cholecystokinin on the cholestasis associated with total parenteral nutrition in experimental short bowel]. / Efecto de la administración de colescistoquinina sobre la colestasis asociada a la nutrición parenteral total en el intestino corto experimental.

INTRODUCTION: Total parenteral nutrition (TPN) is not free of complications. One of the most serious is cholestasis; the cause of this complication is unclear but it may be due to a lack of an enteral stimulus for cholecystokinin (CCK) production. CCK is essential for contraction of the gallbladder and also stimulates intrahepatic bile flow. Its absence may contribute to cholestasis. After any hepatic aggression, the Kupffer cells respond and release proinflammatory cytokines, such as interleukin-1 (IL-1) and tumour necrosis factor alpha (TNF-alpha), which increase the hepatic damage. The objective of this experimental study has been to observe the effect that the exogenous administration of CCK could have on hepatic damage in experimental short bowel with and without TPN, determined using the serum levels of IL-1 and TNF-alpha. MATERIAL AND METHODS: A resection of 80% of the small bowel was performed on 53 Wistar rats and a continuous infusion of saline or TPN was initiated. The rats were divided into the following groups: SHAM (N = 14): normal saline infusion and free access to food and water. TPN (N = 15): Standard TPN. SHAM-CCK (N = 14): same as the SHAM group but with a daily dose of CCK. TPN-CCK (N = 10): same as the TPN group but with a daily dose of CCK. At the end of the experiment, the animals were sacrificed and blood samples were obtained to determine the IL-1 and TNF-alpha values by ELISA. RESULTS: The IL-1 and TNF-alpha levels were higher in the TPN group (7.537 and 5.899 pg/mL, respectively) than in the SHAM group (6.509 and 4.989 pg/mL, respectively) (p > 0.05). The TNF-alpha values were higher in the SHAM group (4.989 pg/mL) than in the SHAM-CCK group (4.583 pg/mL) (p < 0.001). The IL-1 and TNF-alpha levels were higher in the TPN group than in the TPN-CCK group (6.709 and 4.794 pg/mL, respectively) (p < 0.001 for TNF-alpha). CONCLUSIONS: 1. There is a rise in the serum levels of the pro-inflammatory cytokines IL-1 and TNF-alpha in animals with short bowel on TPN or enteral nutrition. 2. The administration of CCK causes a fall in the IL-1 and TNF-alpha levels, and could be used such as a further measure to prevent TPN-associated cholestasis.

Efecto de la administración de colescistoquinina sobre la colestasis asociada a la nutrición parenteral total en el intestino corto experimental / Effect of the administration of cholecystokinin on the cholestasis associated with total parenteral nutrition in experimental short bowel

Introducción. La nutrición parenteral total (NPT) no está libre de complicaciones. Una de las más serias es la colestasis, cuyo origen no es muy claro y puede deberse a la falta de estimulo enteral para la producción de colescistoquinina (CCQ). La CCQ es fundamental para la contracción de la vesícula biliar y como estimulante del flujo biliar intrahepático. Su falta puede contribuir a la colestasis. Ante toda agresión hepática, las células de Kupffer responden y liberan citoquinas proinflamatorias, como la interleukina-1 (IL-1) y el factor de necrosis tumoral alfa (TNF-α), que aumentan el daño hepático. El objetivo de este estudio experimental ha sido observar el efecto que la administración exógena de CCQ pudiera tener sobre el daño hepático en el intestino corto experimental con y sin NPT, medido por los niveles séricos de IL-1 y TNF-α. Material y métodos. Cincuenta y tres ratas Wistar fueron sometidas a una resección del 80% del intestino delgado y a una infusión continua de suero o NPT y se asignaron a los siguientes grupos: • SHAM (N=14): infusión de suero fisiológico y acceso libre a comida y agua. • NPT (N=15): NPT estándar. • SHAM-CCQ (N=14): como el grupo SHAM y una administración diaria de CCQ. NPT-CCQ (N=10): como el NPT y una administración diaria de CCQ. Al final del experimento, los animales fueron sacrificados y se obtuvieron muestra de sangre para determinar los valores IL-1 y TNF-α por ELISA. Resultados. Los niveles de IL-1 y TNF-α fueron mayores en el grupo NPT (7,537 y 5,899 pg/mL, respectivamente) que en el grupo SHAM (6,509 y 4,989 pg/mL, respectivamente) (p > 0,05). Los valores de TNF-α fueron mayores en el grupo SHAM (4,989 pg/mL) que en el grupo SHAM-CCQ (4,583 pg/mL), (p < 0,001). Los niveles de IL-1 y TNF-α fueron mayores en el grupo NPT que en el grupo NPT-CCQ (6,709 y 4,794 pg/mL, respectivamente) (p< 0,001 para TNF-α). Conclusiones. 1. En los animales con intestino corto bajo NPT o con nutrición enteral, se elevan los niveles séricos de las citoquinas proinflamatorias IL-1 y TNF-α. 2. La administración de CCQ, disminuye los niveles de IL-1 y TNF- α, pudiendo ser utilizada como una medida más para combatir la colestasis asociada a la NPT

Introduction. Total parenteral nutrition (TPN) is not free of complications. One of the most serious is cholestasis; the cause of this complication is unclear but it may be due to a lack of an enteral stimulus for cholecystokinin (CCK) production. CCK is essential for contraction of the gallbladder and also stimulates intrahepatic bile flow. Its absence may contribute to cholestasis. After any hepatic aggression, the Kupffer cells respond and release proinflammatory cytokines, such as interleukin-1 (IL-1) and tumour necrosis factor alpha (TNF-α), which increase the hepatic damage. The objective of this experimental study has been to observe the effect that the exogenous administration of CCK could have on hepatic damage in experimental short bowel with and without TPN, determined using the serum levels of IL-1 and TNF-α. Material and methods. A resection of 80% of the small bowel was performed on 53 Wistar rats and a continuous infusion of saline or TPN was initiated. The rats were divided into the following groups: • SHAM (N=14): normal saline infusion and free access to food and water. • TPN (N=15): Standard TPN. • SHAM-CCK (N=14): same as the SHAM group but with a daily dose of CCK. • TPN-CCK (N=10): same as the TPN group but with a daily dose of CCK. At the end of the experiment, the animals were sacrificed and blood samples were obtained to determine the IL-1 and TNF-α values by ELISA. Results. The IL-1 and TNF-α levels were higher in the TPN group (7.537 and 5.899 pg/mL, respectively) than in the SHAM group (6.509 and 4.989 pg/mL, respectively) (p>0.05). The TNF-α values were higher in the SHAM group (4.989 pg/mL) than in the SHAM-CCK group (4.583 pg/mL) (p<0.001). The IL-1 and TNF-α levels were higher in the TPN group than in the TPNCCK group (6.709 and 4.794 pg/mL, respectively) (p< 0.001 for TNF-α). Conclusions. 1. There is a rise in the serum levels of the pro-inflammatory cytokines IL- 1 and TNF-α in animals with short bowel on TPN or enteral nutrition. 2. The administration of CCK causes a fall in the IL-1 and TNF-α levels, and could be used such as a further measure to prevent TPN-associated cholestasis

Descontaminación intestinal selectiva y hepatopatía asociada a nutrición parenteral: estudio experimental / Selective intestinal decontamination and parenteral nutrition related liver disease. Experimental study

La descontaminación intestinal selectiva (DIS) ha demostrado su utilidad para frenar la translocación bacteriana (TB) tanto en modelos animales como en clínica humana. La hepatopatía colostática es un grave problema, de origen poco claro, asociado al intestino corto y al uso prolongado de nutrición parenteral (NP), y en estos pacientes la TB es muy frecuente. Los gérmenes llegan a los ganglios mesentéricos, activan los macrófagos que liberan citoquinas, entre ellas la (..) (AU)

Selective intestinal decontamination (SID) has been useful restraining Bacterial translocation (BT) in both animal models and human clinics. The not well known parenteral nutrition-related liver disease is a serious problem associated to short bowel and long-term parenteral nutrition (PN) use, and BT is also frequent in those patients. Germs reach liver through portal vein and activate Kupffer cells, which release cytokines as IL-1 (..) (AU)

Enterocolitis necrosante y traslocación bacteriana: papel de la nutrición enteral mínima / Necrotizing enterocolitis and bacterial translocation: role of minimal enteral nutrition

Introducción. La enterocolitis necrosante (ECN) y la translocación bacteriana (TB) presentan varias características comunes como son el sobrecrecimiento bacteriano, el déficit inmune y el daño de la mucosa intestinal, los cuales provocan un fallo en la función barrera intestinal. Los principales objetivos de su tratamiento son reducir la mortalidad por sepsis y lograr la tolerancia digestiva los pacientes. En este sentido, la nutrición enteral mínima (NEM) (menos del 25% de las calorías suministradas por ruta enteral), es una técnica usada con frecuencia en neonatos que reciben nutrición parenteral total (NPT), con el objeto de frenar la atrofia de las vellosidades asociadas al ayuno y atenuar sus consecuencias. Objetivo. El objetivo de este trabajo ha sido validar la hipótesis de que la NEM disminuye la incidencia de la TB en un modelo experimental de NPT. Material y métodos. Veinticuatro ratas Wistar adultas fueron sometidas durante 10 días a un régimen de infusión continua de NPT a través de un catéter yugular. Se distribuyeron aleatoriamente en dos grupos: • Grupo Control (n=11): animales en ayunas con infusión de NPT estándar (300 ml/24 h, 280 kcal/kg/24 h), sin acceso a comida y agua. • Grupo NEM (n=13): NPT estándar y dieta oral (hasta 15 g/24 h de pienso, 3,1 kcal/g) y acceso libre a agua. Al final del experimento, los animales fueron sacrificados y se obtuvieron muestras de ganglios linfáticos mesentéricos (GGLL), sangre portal y sangre periférica para su posterior cultivo y diagnóstico de TB, que se definió como la presencia de enterobacterias en cualquiera de los campos observados. Resultados. En el grupo NEM la curva de peso presentó una mejor evolución y la incidencia de la TB disminuyó significativamente, un 8%, frente al 45% del grupo CTRL (p < 0,05). El riesgo relativo (RR) fue de 5,9 (IC 95% 0,81-43,71) y el número necesario a tratar (NNT) fue de 3 (IC 95% 2-20). Conclusiones. La NEM reduce la incidencia de la TB en un modelo experimental de nutrición parenteral, abriéndose como vía de investigación la suposición de que la reducción de la TB puede disminuir el riesgo de sepsis que pueden estar asociadas a la ECN (AU)

Introduction. Both necrotizing enterocolitis (NEC) and bacterial translocation (BT) have in common that bacterial overgrowth, a decrease in immunity and intestinal mucosal damage, followed by a barrier failure, can act as trigger factors. The main objectives in NEC treatment are to reduce mortality due to sepsis and to promote feeding tolerance. To achieve that, Minimal Enteral Nutrition (MEN) (less than 25% of the calories provided by enteral route) is a more and more used technique in newborns who receive Parenteral Nutrition (PN) to slow down fasting related villi atrophy and to attenuate its consequences. Aim. To test the hypothesis that MEN decreases BT in an experimental model of PN. Methods. Twenty-four adult Wistar male rats received a continuous infusion of all-in-one PN solution through a jugular vein catheter. The animals were randomly divided in two groups and maintained in individual metabolic cages for ten days. • Control group (N=11): fasting rats receiving, standard PN (300 mL/kg/24 h, 280 kcal/ kg/24 h). • MEN group (N=13): standard PN and rat chow (15 g /24 h, 3,1 kcal/g). At the end of the experiment animals were sacrificed and mesenteric lymph nodes (MLN), and both peripheral and portal blood samples were recovered and cultured. Bacterial identification in blood was carried out by conventional methods and MLN culture was considered positive with a growth over 100 Colony Forming Units/g. Results. Weight curve was better in MEN group and BT was also significantly reduced. Translocation was found in 45% of control group and 8% of MEN group (p < 0,05). The relative risk (RR) was 5,9 (IC 95% 0,81-43,71) and the number needed to treat (NNT) was 3 (95% CI 2-20). Conclusions. 1. MEN reduces the incidence of BT in an experimental model of parenteral nutrition. 2. BT reduction could decrease NEC-related sepsis risk (AU)

[Selective intestinal decontamination and parenteral nutrition related liver disease. Experimental study]. / Descontaminación intestinal selectiva y hepatopatía asociada a nutrición parenteral: estudio experimental.

Selective intestinal decontamination (SID) has been useful restraining Bacterial translocation (BT) in both animal models and human clinics. The not well known parenteral nutrition-related liver disease is a serious problem associated to short bowel and long-term parenteral nutrition (PN) use, and BT is also frequent in those patients. Germs reach liver through portal vein and activate Kupffer cells, which release cytokines as IL-1 or TNF-alpha. The aim of this study was to test the use of SID restraining BT in a PN undergoing experimental short bowel model, and its possible favourable consequences on hepatic injury determined by IL-1 and TNF-alpha levels. Twenty-five 240-280 g Wistar rats were divided into two groups and maintained in individual metabolic cages for ten days: Resection-PN group (n=15): animals with a bowel resection of the 80% and a continuous PN infusion. Resection-PN-SID (n=10) group: similar to previous group and a daily oral administration of Tobramycine (20mg/kg/day) and Polymyxine-E (25mg/kg/day). Animals were sacrificed and mesenteric lymph nodes (MLN), and both peripheral and portal blood samples were recovered for TB determination in bacterial culture. Determination of both IL-l and TNF-alpha seric levels were carried out by ELISA. Bacterial translocation incidence was higher in RES-NPT group (66.6%) than RES-NPT-SID group (30%) (P>0,05). The relative risk was 2.22 (IC 95% 0,81-6,11) and the number needed to treat was 3 (IC 95% 2-235). Seric levels of IL-1 and TNF-alpha were also higher in RES-NPT group (7,537 and 5,399 pg/ml, respectively) than in RES-NPT-SID group (6,397 and 5,032 pg/ml respectively) (p<0,001). 1. SID reduces TB in a PN undergoing experimental short bowel resection murine model. 2. Parenteral nutrition-related liver disease decreases in DIS receiving animals.

[Necrotizing enterocolitis and bacterial translocation: role of minimal enteral nutrition]. / Enterocolitis necrosante y traslocación bacteriana: papel de la nutrición enteral mínima.

INTRODUCTION: Both necrotizing enterocolitis (NEC) and bacterial translocation (BT) have in common that bacterial overgrowth, a decrease in immunity and intestinal mucosal damage, followed by a barrier failure, can act as trigger factors. The main objectives in NEC treatment are to reduce mortality due to sepsis and to promote feeding tolerance. To achieve that, Minimal Enteral Nutrition (MEN) (less than 25% of the calories provided by enteral route) is a more and more used technique in newborns who receive Parenteral Nutrition (PN) to slow down fasting related villi atrophy and to attenuate its consequences. AIM: To test the hypothesis that MEN decreases BT in an experimental model of PN. METHODS: Twenty-four adult Wistar male rats received a continuous infusion of all-in-one PN solution through a jugular vein catheter. The animals were randomly divided in two groups and maintained in individual metabolic cages for ten days. * Control group (N= 1): fasting rats receiving, standard PN (300 mL/kg/ 24 h, 280 kcall kg/24 h). * MEN group (N=13): standard PN and rat chow (15 g /24 h, 3,1 kcal/g). At the end of the experiment animals were sacrificed and mesenteric lymph nodes (MLN), and both peripheral and portal blood samples were recovered and cultured. Bacterial identification in blood was carried out by conventional methods and MLN culture was considered positive with a growth over 100 Colony Forming Units/g. RESULTS: Weight curve was better in MEN group and BT was also significantly reduced. Translocation was found in 45% of control group and 8% of MEN group (p < 0,05). The relative risk (RR) was 5,9 (IC 95% 0,81-43,71) and the number needed to treat (NNT) was 3 (95% CI 2-20). CONCLUSIONS: 1. MEN reduces the incidence of BT in an experimental model of parenteral nutrition. 2. BT reduction could decrease NEC-related sepsis risk.

[Incidence of bacterial translocation in four different models of experimental short bowel syndrome]. / Incidencia de la traslocación bacteriana en cuatro modelos diferentes de intestino corto experimental.

UNLABELLED: The outcome of patients with short bowel syndrome is influenced for factors such as the length of remnant intestine or the presence or absence of ileocecal valve (ICV). Gram-negative sepsis, the main cause of mortality in this group of children, is probably due to bacterial translocation (BT), because after gut resection there are a number of circumstances that favour its occurrence, being the most known intestinal dismotility, bacterial overgrowth, loss of gut-associated lymphoid tissue, total parenteral nutrition (TPN) and fasting related mucosal atrophy. The aim of this experimental controlled study was to test the incidence of BT after four different types of gut resection, in animals fed orally or receiving TPN. Hundred and three adult Wistar rats bred and raised in our facilities according to European Union Regulations were randomly divided in six groups:--Group 1 (n = 26): non-manipulated animals, served as a control.--Group 2 (n = 14): 80% non-lethal small bowel resection, fed orally.--Group 3 (n = 15): same resection as group 2 but including ICV. Rat chow ad libitum.--Group 4 (n = 27): non-resected fasting animals receiving all-in-one TPN solution.--Group 5 (n = 11): same resection as group 2, but fasting and receiving TPN--Group 6 (n = 10): 90% small bowel resection, including cecum and ICV, fasting and TPN. The animals were maintained for 10 days in individual metabolic cages, and, at the end of the experiment, were bled by portal and cardiac puncture. Mesenteric lymph nodes, peripheral and portal blood samples were cultured for BT. Non-manipulated rats (group 1) had lower BT incidence (8%) than resected ones (groups 2, 3, 5 and 6, 93%, 60%, 91%, 60%, p < 0.05) or animals non-resected, receiving TPN (group 4.51%, p < 0.05). When resection included ICV in orally fed rats BT index was also lower (group 3 vs group 2.60% vs 91%, p < 0.05). In TPN resected animals a drop was also found in BT when ICV and cecum were added to small bowel resection (group 6 vs group 5.60% vs 91%, p < 0.05). IN CONCLUSION: 1. Gut resection is associated to a high degree of BT, even if the animals are fed orally. 2. Resection including ICV, produced less BT. 3. TPN-related BT was shown in half of the animals non resected. 4. TPN-resected rats had also less BT when ICV and cecum were removed.

Incidencia de la traslocación bacteriana en cuatro modelos diferentes de intestino corto experimental / Incidence ofbacterial translocation in four differentmodels ofexperimental short bowel syndrome

La longitud del intestino remanente o la presencia o ausencia de la válvula ileocecal (VIC) así como el riesgo de infección afectan a la evolución de los pacientes con síndrome de intestino corto en los que, además, la dismotilidad, o el sobrecrecimiento bacteriano favorecen la aparición de traslocación bacteriana (TB).El objetivo de este trabajo experimental controlado fue estudiar la incidencia de la TB, en cuatro modelos diferentes de resección intestinal, en animales con alimentación oral o bajo nutrición parenteral total (NPT).Se utilizaron 103 ratas Wistar que se asignaron aleatoriamente a 6 grupos: Grupo 1 (n=26): grupo control, animales sin ningún tipo de manipulación. Grupo 2 (n=14): resección no letal del 80% del intestino delgado y alimentación oral. Grupo 3 (n=15): como el grupo 2, pero añadiendo a la resección la VIC. Grupo 4 (n=27): sin resección intestinal, mantenidos exclusivamente con NPT. Grupo 5 (n=11): resección (..) (AU)