Tratamiento endoscópico del reflujo vesicoureteral: hallazgos histológicos / Endoscopic treatment of vesicoureteral reflux: histologic findings

Objetivo: El reflujo vesicoureteral es una patología con diferentes formas de manejo terapéutico, una de las cuales es la inyección vía endoscópica de diferentes materiales. Mostramos algunos cambios histológicos que producen estos materiales en la pared vesical. Métodos: Estudiamos 3 muestras de uréter intravesical en 3 niños afectos de reflujo vesicoureteral. Las muestras se obtuvieron durante la reimplantación de los uréteres, extirpando la porción más distal de los uréteres. Resultados: Mostramos los cambios encontrados con los diferentes materiales estudiados (politetrafluoroetileno, polidimetilsiloxano, copolímero de dextranómero y ácido hialurónico) observando una menor formación de tejido conjuntivo con los 2 últimos. Conclusiones: Se describen migraciones y granulomas con diferentes materiales y se constata la reacción de cuerpo extraño y fibrosis en la pared vesical. Son necesarios más estudios en humanos para determinar el mejor producto de inyección endoscópica (AU)

Objectives: Vesicoureteral reflux is a pathologic entity with different forms of therapeutic management, one of which is endoscopic injection of various materials. We show some histological changes produced by these materials in the bladder wall. Methods: We study three samples of intravesical ureter from three children suffering vesicoureteral reflux. The ureters were obtained during ureteral reimplantation surgery. Results: We show the changes found with various materials under study (polytetrafluorethylene, polydimethylsiloxane, hyaluronic acid and dextranomer copolimer) observing less conjunctive tissue with the two latter and with the more encapsulated hyaluronic acid - dextranomer copolimer. Conclusions: Migrations and granulomas are described with various materials and we ascertained the presence of foreign body reaction and fibrosis within the bladder wall. More studies in human beings are required to determine the best product for endoscopic injection (AU)

Tratamiento de reflujo vesicoureteral / The treatment of vesicoureteral reflux

Objetivo: El reflujo vesicoureteral (RVU) es una patología frecuente, con una incidencia de 29/50% en niños estudiados por infección del tracto urinario (ITU) y de 20% en recién nacidos con diagnóstico pre-natal de hidronefrosis. A lo largo de los años, la terapéutica ha sido motivo de muchas reuniones, de muchos trabajos de investigación y continúa siendo un tema discutido. Con el desarrollo de técnicas endoscópicas de mínima invasión, por inyección sub-ureteral de “bulking agents”, el grupo de candidatos a tratamiento quirúrgico aumentó. Presentamos los resultados del tratamiento quirúrgico de RVU de 2001 a 2006. Métodos: Se realizó un estudio retrospectivo de tratamiento endoscópico de RVU con inyección sub-ureteral de copolimero de dextranomero ácido hialurónico (Copol-Dx/AH). Se incluyeron todos los niños tratadas en el periodo comprendido entre 1/ Julio/ 2001 a 30/ Diciembre/ 2006. El tratamiento se realizó en niños con un reflujo mínimo de grado II o superior. Se consideró tratados a los pacientes que presentaban una CUMS de control sin reflujo o con reflujo vesico ureteral grado I, proponiéndose en estos casos la suspensión de la profilaxis antibiótica de ITU. Resultados: Se trataron 661 niños, 607 por vía endoscopia y 54 por técnica de Cohen. De los niños tratados endoscopicamente, 437 eran de sexo femenino y 170 de sexo masculino. El RVU era bilateral en 37,7% de los casos, siendo el grado II el más frecuente (40% en el sexo masculino y 57% en el femenino). La tasa global de éxito fue de 70% después del primer tratamiento, de 75% después del segundo tratamiento y subió para 78% después del tercero. Conclusiones: La inyección sub-ureteral de copolímero de dextranomero ácido hialurónico es un tratamiento eficaz en niños con RVU, con indiferencia del grado de reflujo. Es un procedimiento sencillo, seguro, bien tolerado y con baja morbilidad. Es, en este momento, el tratamiento quirúrgico de elección en la mayor parte de los pacientes con RVU (AU)

Objectives: Vesicoureteral reflux (VUR) is a frequent pathology, with an incidence of 29/50% in children studied for urinary tract infection (UTI) and 20% of newborns with the diagnosis of prenatal hydronephrosis. Over the years, the treatment has been the subject of many meetings, many research studies, and continues being a topic under discussion. The number of candidates for surgical treatment increased with the development of minimally invasive endoscopic techniques by subureteral injection of bulking agents. We present the results of the surgical treatment of VUR between 2001 and 2006. Methods: We performed a retrospective study of the endoscopic treatment of VUR by subureteral injection of Dextranomer and hyaluronic acid copolymer (Copol-Dx/AH). All children undergoing treatment between July 1st 2001 and December 30th 2006 were included in this study. Treatment was performed in children with VUR grade II or greater. All patients presenting no reflux or grade I VUR on control VCUG were considered cured; stopping antibiotic prophylaxis was proposed in these cases. Results: 661 children underwent treatment, 607 endoscopic and 54 with the Cohen technique. Among children treated endoscopically, 437 where females and 170 males. VUR was bilateral in 37.7% of the cases, with grade II being the most frequent (40% in males and 57% in females). Overall success rate was 70% after first treatment, 75% after second treatment and increased to 78% after the third. Conclusions: Subureteral injection of dextranomer and hyaluronic acid copolymer is an effective treatment in children with VUR, independently of the grade. It is a simple, safe, well tolerated procedure with low associated morbidity. Currently, it is the surgical treatment of choice in most patients with VUR (AU)

Endoscopic treatment of vesicoureteral reflux in the previously reimplanted ureter: technical aspects and results / Tratamiento endoscópico del reflujo vesicoureteral en el uréter previamente reimplantado: aspectos técnicos y resultados

Objectives: To assess the feasibility and results of the endoscopic treatment of vesicoureteral reflux (VUR) after a failed ureteral reimplantation. Methods: From January 1996 to October 2006, 28 patients underwent endoscopic treatment for VUR grade II to V persisting after open ureteral reimplantation. VUR was bilateral in 11 patients, for a total of 39 ureteral units (UU) treated. The endoscopic treatment was performed 1 to 7 years after surgery (average 2.5 years). Dextranomer/Hyaluronic acid Copolymer (Dx/HA) was used as injectable material. The amount of injected material ranged from 0.5 to 2.8 ml (average: 1.2 ml). Some technical refinements were required to increase the success of the procedures. Patients were followed up from 2.5 to 17 years. Voiding cystourethrogram (VCUG) was performed at 6 months and MAG3 renal scan with voiding phase at 24 months. Results were compared with the outcome of the endoscopic treatment in patients treated by the same surgeons for primary VUR, matched for grade (control group). Results: All treatments were performed as one-day procedure. No complications were observed. Success was achieved in 22/28 patients (78.5%) and in 30/39 UU (76.9 %) after failed ureteral reimplantation. No significant difference in success rate was found from the control group (p= ns). Conclusions: Endoscopic treatment of VUR after a failed reimplantion can be a challenging procedure, for a skilled endoscopists. Nonetheless it can achieve successful results in a high percentage of patients with minimal morbidity and a minimal invasiveness; it should thus be recommended for these patients (AU)

Objetivo: Evaluar la viabilidad y resultados del tratamiento endoscópico del reflujo vesicoureteral (RVU) después del fracaso del reimplante ureteral. Métodos: Entre enero de 1996 y octubre del 2006, 28 pacientes fueron sometidos a tratamiento endoscópico del RVU persistente grados II a V después de reimplante ureteral. El RVU era bilateral en 11 pacientes, con un total de 39 uréteres tratados. El tratamiento endoscópico se realizó entre 1 y 7 años después de la cirugía (media 2,5 años). Como material inyectable se utilizó copolímero de ácido hialurónico/dextranomero. La cantidad de material inyectado varió entre 0,5 y 2,8 ml (media 1,2 ml). Fue necesaria alguna finura técnica para aumentar el éxito de los procedimientos. Los pacientes fueron seguidos entre 2,5 y 17 años. Se realizó cistouretrografía miccional seriada (CUMS) a los seis meses y gammagrafía renal MAG3 con fase miccional a los 24 meses. Los resultados se compararon con los de un grupo control de tratamiento endoscópico en pacientes con RVU primario tratados por los mismos cirujanos, emparejados según el grado. Resultados: Todos los tratamientos fueron realizados de forma ambulatoria. No se observaron complicaciones. Se obtuvo el éxito en 22/28 pacientes (78 .5%) y en 30/39 uréteres (76. 9%) después de un reimplante fallido. No hubo diferencias significativas en las tasas de éxitos comparando con el grupo control (p =ns). Conclusiones: El tratamiento endoscópico del RVU después del fracaso de un reimplante puede ser un desafío para un endoscopista experto. Sin embargo puede conseguir resultados exitosos en un alto porcentaje de pacientes con mínima morbilidad en pasividad. Por tanto, debería recomendarse en estos pacientes (AU)

Modification of the sting procedure for vesicoureteral reflux: ureteral repositioning and injection / Modificación del procedimiento de inyección subureteral estándar (STING) para el reflujo vesico ureteral: reposicionamiento ureteral e inyección

Objetive: Over the past 20 years endoscopic treatment (ET) of vesicoureteral reflux (VUR) has changed the algorithm of reflux management. We describe a modification of the standard subureteral injection (STING) that has contributed to the increased success rate of this procedure. Methods: Between January 2006 and December 2006 192 children, 5 months to 10 years old (mean age 2.8 years) underwent endoscopic treatment for VUR, with injection of dextranomer/hyaluronic acid copolymer (Dx/HA). Standard STING procedure was used in 165 patients (235 ureters). A modified STING procedure, here described as “ureteral repositioning and injection” (URI) was used in 27 patients (38 ureters). In the URI technique, the needle was inserted as for standard STING; subsequently the distal part of the ureter was raised and levered towards the lumen of the bladder; Dx/HA was then injected. Renal/bladder ultrasound was performed 1 month after treatment and a voiding cystourethrogram (VCUG) at 4-6 months. Results: After a single injection the VCUG showed no reflux in 203 ureters of STING group (86%) and in 34 ureters of URI group (91%). Mean injected volume of Dx/HA was 0.7 ml (0.3 - 1.8 ml) for STING and 0.4 ml (0.3 - 0.8 ml) for URI. Conclusion: The modified STING we have proposed, presents some advantages. It is very easy to perform and needs less material to inject. The ureteral repositioning into the bladder, with the support of the implanted material, may reconstruct a true flap-valve mechanism, without the risk of ureteral obstruction (AU)

Objetivo: Durante los últimos 20 años el tratamiento endoscópico del reflujo vesicoureteral (RVU) ha cambiado el algoritmo del manejo de esta entidad. Describimos una modificación de la inyección subureteral estándar (STING) que ha contribuido a aumentar el porcentaje de éxitos de este procedimiento. Métodos: Entre enero y diciembre del 2006, 192 niños, entre cinco meses y diez años de edad (edad mediana 2,8 años), fueron sometidos a tratamiento endoscópico del reflujo vesico ureteral con inyección de copolímero de dextranomero/ácido hialurónico (DX/HA). El procedimiento STING estándar se utilizó en 165 pacientes (235 uréteres). Un procedimiento STING modificado, descrito aquí como “reposicionamiento ureteral e inyección” (RUI) se utilizó en 27 pacientes (38 uréteres). En la técnica de reposicionamiento ureteral e inyección se inserta la aguja como para un procedimiento STING estándar y posteriormente se eleva la porción distal del uréter haciendo palanca hacia la luz vesical y entonces se inyecta el DX/HA. Se realizó ecografía renal/vesical un mes después del tratamiento y una cistouretrografía miccional seriada (CUMS) a los 4-6 meses. Resultados: Después de una única inyección la CUMS mostró ausencia de reflujo en 203 uréteres del grupo STING (86%) y 34 uréteres del grupo RUI (91%).El volumen medio de DX/HA inyectado fue de 0,7 ml (0,3-1,8 ml) en el STING y 0,4 ml (0,3-0,8 ml) en el RUI. Conclusiones: La modificación del STING que proponemos tiene algunas ventajas. Es muy fácil de realizar y necesita menos material inyectable. El reposicionamiento ureteral hacia la vejiga, con el apoyo del material implantado, puede reconstruir un auténtico mecanismo de válvula-flap sin riesgo de obstrucción ureteral (AU)

Vantris®, a biocompatible, synthetic, non-biodegradable, easy-to-onject bulking substance. Evaluation of local tissular reaction, localized migration and long-distance migration / Vantris® una sustancia inyectable biocompatible, sintética, no biodegradable y fácil de aplicar: Evaluación de la reacción tisular local, y de la migración local y a larga distancia

Biodegradable injectable bulking agents of animal origin present a fast rate of bio-reabsorption and may cause an allergic reaction. Biodegradable elements of synthetic origin have a high rate of reabsorption after a year. Non-biodegradable agents of synthetic origin lead to the formation of a fibrotic capsule, giving stability and long-term permanence. VANTRIS® is categorized into this last group; it belongs to the family of Acrylics, particles of polyacrylate polyalcohol copolymer immersed in a glycerol and physiological solution carrier. Molecular mass is very high. When injected in soft tissues, this material causes a bulkiness that remains stable through time. The carrier is a 40% glycerol solution with a pH of 6. Once injected, the carrier is eliminated by the reticular system through the kidneys, without metabolizing. Particles of this polyacrylate polyalcohol with glycerol are highly deformable by compression, and may be injected using a 23-gauge needle. The average of particles size is 320 mm. Once implanted, particles are covered by a fibrotic capsule of up to 70 microns. Particles of this new material are anionic with high superficial electronegativity, thus promoting a low cellular interaction and low fibrotic growth. The new polyacrylate polyalcohol copolymer with glycerol was tested for biocompatibility according to ISO 10993-1:2003 in vitro, showing that they are not mutagenic for the Salmonella T. strains analyzed. The extract turned out to be non-cytotoxic for cell lines in culture and non-genotoxic for mice. In in vivo studies, acrylate did not cause sensitization in mice. The macroscopic reaction of tissue irritation was not significant in subcutaneous implants and in urethras of rabbits. Seven female dogs were injected transurethrally with VANTRIS® to evaluate short and long-term migration (13 weeks and 12 months respectively). No particles or signs of inflammation or necrosis are observed in any of the organs examined 13 weeks and 12 months after implantation. To conclude, this new material meets the conditions of ideal tissue bulking material (AU)

Los agentes inyectables biodegradables de origen animal presentan una tasa rápida de bioreabsorción y pueden provocar reacciones alérgicas. Los elementos biodegradables de origen sintético tienen una alta tasa de reabsorción después de un año. Los agentes no-biodegradables de origen sintético dan lugar a la formación de una cápsula fibrótica, dando estabilidad y permanencia a largo plazo. VANTRIS® se clasifica en este último grupo; pertenece a la familia de los acrílicos, partículas de copolímero poliacrida polialcohol inmersas en una solución vehiculante de glicerol y fisiológico. Su masa molecular es muy alta. Cuando se inyecta en tejidos blandos, este material produce un abultamiento que permanece estable a lo largo del tiempo. El vehículo contiene un 40% de solución de glicerol con un pH de 6. Una vez inyectada, el vehículo es eliminado por el sistema reticular a través de los riñones, sin metabólizar. Las partículas de este poliacrilato polialcohol con glicerol son altamente deformables por compresión, y pueden inyectarse utilizando una aguja del 23 Gauge. El tamaño medio de las partículas es de 320 mm. Una vez implantadas, las partículas se recubren de una cápsula fibrótica de hasta 70 micrones. Las partículas de este nuevo material son aniónicas y tienen una gran electronegatividad en superficie, promoviendo así una baja interacción celular y un bajo crecimiento fibrótico. El nuevo copolímero de poliacrilato polialcohol con glicerol fue sometido a pruebas de biocompatibilidad in vitro de acuerdo con la normal ISO 10993-1:2003, mostrando que no es mutagénico para las cepas de salmonela T. analizadas. El extracto no fue citotóxico en cultivos de líneas celulares ni en ratones. En los estudios in vivo, el acrilato no produjo sensibilización en ratones. Los implantes subcutáneos y en uretra de conejos no produjeron reacción de irritación tisular macroscópica significativa. Para evaluar la migración a corto y largo plazo se inyectó Vantris® por vía transuretral en siete hembras de perro (13 semanas y 12 meses respectivamente). No se observaron partículas o signos de inflamación con necrosis en ninguno de los órganos examinados ni a las 13 semanas ni a las 12 meses del implante. En conclusión, este nuevo material cumple con las condiciones del material inyectable tisular ideal

Tratamiento endoscópico del reflujo vésicoureteral en pacientes pediátricos diagnosticados de vejiga neurógena. Resultados y evolución a largo plazo / Endoscopic treatment of vesicoureteral reflux in pediatric patients with the diagnosis of neurogenic bladder. Results and long-term outcome

Objetivo: Conocer los resultados, complicaciones y la evolución de ocho pacientes diagnosticados de Vejiga neurógena (VN), intervenidos de Reflujo vesicoureteral (RVU) mediante la inyección subureteral de sustancias inertes, intentando precisar su indicación en el esquema terapéutico de la alteración vesical neurógena. Métodos: Revisión retrospectiva de los resultados obtenidos y de las complicaciones evidenciadas durante los controles evolutivos efectuados a ocho pacientes en edad pediátrica con VN secundaria a diferentes patologías, diagnosticados de RVU, tratado mediante inyección subureteral de pasta de teflón (1 caso), polidimetilsiloxano (6) y copolímero de dextranómero y ácido hialurónico (1). Resultados: De los 11 uréteres tratados en 8 (72.7%) el RVU curó después de la primera inyección. De los 3 uréteres con persistencia del RVU, en dos cesó después del segundo tratamiento endoscópico (TE). La eficacia del TE después de la segunda inyección alcanzó el 90.9%. En dos casos unilaterales evidenciamos RVU contralateral que curó mediante TE en uno siguiendo pauta conservadora el segundo. Durante el periodo de seguimiento (tiempo medio: 51.8 +/- 28.5 meses) presentaron complicaciones 4 casos. Reapareció el RVU en dos, observamos RVU contralateral en uno a los 19 meses del primer tratamiento y en otro evidenciamos ureterohidronefrosis bilateral con infecciones urinarias recurrentes que precisó de cistoplastia de aumento. Conclusiones: El TE es una opción eficaz cuando se decide el tratamiento quirúrgico del RVU en un paciente con vejiga neurógena. Es necesario seguir la evolución a largo plazo de los pacientes intervenidos, sobre todo aquellos con capacidad y acomodación vesical alterada y uretra activa o disinérgica, ante la posibilidad de aparición del RVU ya curado (AU)

Objectives: To know the results, complications and outcomes of eight patients with the diagnosis of neurogenic bladder (NB) who underwent vesicoureteral reflux surgery by subureteral injection of inert substances, trying to precise its indication in the therapeutic scheme for neurogenic bladder dysfunction. Methods: Retrospective review of the results and complications recorded during follow-up in eight pediatric patients with NB secondary to various pathologies and the diagnosis of VUR treated by subureteral injection of Teflon paste (1 case), polydimethylsiloxane (6) and dextranomer/hyaluronic acid copolymer (1). Results: In 8 (72.7%) of the 11 ureters treated VUR was cured after first injection. VUR stopped after second endoscopic treatment in 2 of the 3 ureters with persistent VUR. The efficacy of endoscopic treatment after second injection achieved 90.9%. In 2 unilateral cases we observed contralateral VUR, which cured in one case after endoscopic treatment and the other one followed a conservative scheme. Over the follow-up period (Mean FU time 51.8+/- 28.5 months) 4 cases presented complications. VUR recurred in two: in one contralateral VUR was detected 19 months after first treatment, the other one presented bilateral ureterohydronephrosis with recurrent urinary tract infections and required augmentation cystoplasty. Conclusions: Endoscopic treatment is an effective option when choosing surgical treatment for VUR in a patient with neurogenic bladder. It is necessary to follow the long-term outcome of patients after surgery, mainly those with abnormal bladder capacity and compliance and active or dyssynergic urethra due to the possibility of recurrence of the VUR (AU)

Eficacia del tratamiento endoscópico del reflujo vesicoureteral secundario. Análisis de una serie de 142 casos / The efficacy of endoscopic treatment for secondary vesicoureteral reflux. Analysis of a series of 142 cases

Objetivo: Analizar la proporción de reflujos vesicoureterales secundarios o complicados del total de reflujos vesicoureterales tratados en nuestro centro. Determinar la eficacia del tratamiento endoscópico en dicho tipo de reflujo según la etiología que lo produce y según el grado. Método: Revisamos nuestra serie desde que iniciamos el tratamiento endoscópico del reflujo en el año 1992 hasta diciembre del 2006, empleando tres materiales distintos: pasta de politetrafluoroetileno (Teflon®), polidimetilsiloxano (Macroplastique®) y dextranómero-copolímero de ácido hialurónico (Deflux®). Hemos tratado a 402 pacientes y 479 unidades excretoras, de los que 124 pacientes y 142 unidades excretoras correspondían a una etiología secundaria. Se han seguido de forma sistemática mediante ecografía y CUMS o cistografía isotópica. Definimos el éxito del tratamiento como la desaparición del RVU o el descenso a grado I sin ITU tras retirar la profilaxis antibiótica. Resultados: Se resolvieron en el primer intento el 71,13% de los reflujos secundarios, mejorando al 85,92% en el segundo intento y al 90,14% en el tercero. El volumen medio inyectado ha sido de 0,65 ml. La tasa de complicaciones ha sido del 0%. Conclusiones: El tratamiento endoscópico del reflujo vesicoureteral secundario es un procedimiento minimamente invasivo, que puede realizarse en regimen ambulatorio, técnicamente algo más difícil que en los casos de reflujo vesicoureteral primario, pero con muy baja morbilidad y muy eficaz en casos seleccionados, por lo que pensamos que debe ser considerado la primera opción de tratamiento. La menor eficacia la hemos obtenido en los casos de reflujos secundarios a vejiga neurógena, probablemente en relación a un mal control de las altas presiones vesicales (AU)

Objectives: To evaluate the rate of secondary or complicated vesicoureteral reflux (VUR) among the total number of VUR cases treated in our institution. To determine the efficacy of the endoscopic treatment in secondary or complicated VUR depending on etiology and grade. Method: We review our experience with endoscopic treatment for VUR from 1992 to 2006. We have used three different materials: polytetrafluoroethylen (Teflon®), polydimethylsiloxane(Macroplastique®) and dextranomer/hyaluronic acid copolymer (Deflux®). 479 ureters with VUR were treated in 402 patients ; 124 patients and 142 ureters of them were secondary or complicated VUR cases. All patients were followed up with urinary tract ultrasound and radiological or isotopic voiding cystogram. Success is defined as VUR disappearance or improvement to grade I VUR without urinary infection after removing antibiotic prophylaxis. Results: The success rate has been 71.13% after the first injection, 85.92% after the second injection and 90.14% after the third injection. Mean subureteral dose has been 0.65 ml. The complications rate has been 0%. Conclusions: The endoscopic treatment in secondary or complicated VUR is a minimally invasive procedure. It seems to be more difficult than in primary VUR cases, but its low morbidity and efficacy indicate this may be a proper first option in selected patients. In cases of VUR secondary to neurogenic bladder dysfunction it seems to be less successful, probably because of a worse control of the high bladder pressure (AU)

Una buena solución para un mal caso / A good solution for a bad case

Se presenta el caso de un varón afecto de reflujo, después de haber realizado un reimplante ureteral y aún después de haberle realizado un tratamiento endoscópico adicional. Al realizar una segunda cistoscopia para practicar un nuevo tratamiento endoscópico, se descubrió un orificio en el tercio medio del túnel del reimplante ureteral previo que actuaba de «shunt» y mantenía el reflujo. El paciente fue tratado exitosamente mediante la oclusión del orificio que mantenía este reflujo con una nueva inyección de «Dextranómero/Nasha» (AU)

We present the case of a child presenting vesicoureteral reflux after ureteral reimplantation and endoscopic treatment. In a second cistoscopy to repeat endoscopic treatment a new orifice in the medium third of the tunnel of the previous ureteral reimplantation was discovered. This orifice acted as a shunt and maintained reflux. The patient was treated by further occlusion of the orifice with another injection of «tranómero/Nasha» (AU)

Nonspecific stimulation of the maternal immune system. I. Effects On teratogen-induced fetal malformations.

BACKGROUND: Maternal immune stimulation has reported, but unconfirmed, efficacy for reducing chemical-induced morphologic defects in mice. METHODS: Teratogenic chemicals (2,3,7, 8-tetrachlorodibenzo-p-dioxin [TCDD], ethyl carbamate [urethane], methylnitrosourea [MNU], or valproic acid [VA]) were given to pregnant mice to induce cleft palate (TCDD, urethane), digital defects (urethane, MNU), or exencephaly (VA). Before teratogen administration, the immune system of female mice was stimulated by intraperitoneal (IP) administration of pyran copolymer or attenuated bacillus Calmette Guérin (BCG), or by footpad injection with Freund's complete adjuvant (FCA). RESULTS: Fetal defects caused by all four chemicals studied were reduced by maternal immunostimulation, sometimes dramatically. In addition to reducing VA-induced exencephaly, immunostimulation with FCA resulted in fetal mice displaying anury (absence of tails). Activated maternal immune cells could not be detected in fetal circulation using flow cytometry and a fluorescent cell-tracking probe. CONCLUSIONS: For the chemicals tested, maternal immune stimulation has efficacy in reducing fetal defects. Immune protection against teratogenesis may be an indirect effect of maternal immune cell activation.

Prevention of hepatic ischemia-reperfusion injury by SOD-DIVEMA conjugate.

A protective effect of the SOD (superoxide dismutase)-DIVEMA (divinyl ether and maleic anhydride) conjugate on I-R (ischemia-reperfusion) liver injury was demonstrated. Twenty minutes of normothermic hepatic ischemia was induced by clamping the portal triad of Sprague-Dawley rats. Five minutes before the end of ischemia, SOD, SOD-DIVEMA, or NaCl (0.9%) was given intravenously. Using intravital fluorescence microscopy, hepatic microvascular perfusion was analyzed before ischemia and repeatedly during the 120-min reperfusion period. SOD-DIVEMA significantly restored the sinusoidal perfusion rate (control, 98.0 +/- 0.5; NaCl, 65.5 +/- 7. 7; SOD, 81.5 +/- 8.2; SOD-DIVEMA, 95.8 +/- 0.7%) and reduced the number of leukocytes stagnant in acini (control, 4.4 +/- 0.9; NaCl, 36.6 +/- 6.3; SOD, 27.7 +/- 6.8; SOD-DIVEMA, 12.3 +/- 3.3 cells/lobule) and adherent in postsinusoidal venules (control, 55.0 +/- 24; NaCl, 417 +/- 63; SOD, 253 +/- 58; SOD-DIVEMA, 40.0 +/- 14 cells/mm2). In addition, SOD-DIVEMA maintained postischemic hepatocellular integrity. The SOD-DIVEMA-treated group revealed higher serum SOD enzyme activity compared to the SOD group after 120 min of reperfusion (SOD-DIVEMA, 33.0 +/- 5.9; SOD, 8.6 +/- 3.1 U/ml). The beneficial effect of SOD-DIVEMA was most prominent after 120 min of reperfusion, indicating a longer intravascular half-life of SOD-DIVEMA.

An effective tumor vaccine against malignant melanoma: irradiated autologous tumor cells admixed with MVE-2.

The aim of this study was to develop as effective as possible autologous tumor vaccine which would be at the same time easy to produce, highly controllable, and without undesired side effects on normal tissue. Therefore, irradiated autologous - syngeneic B-16 tumor cells admixed with a non-specific immunomodulator MVE-2 (a polymer fraction of 1,2-co-polymer of divinyl ether and maleic anhydride) were used for subcutaneous (s.c.). or intraperitoneal (i.p.) prevaccination of experimental mice. Compared to the control mice, a statistically significant delay in tumor development of s.c. tumors was achieved in prevaccinated mice (p<0.05). An even better effect was observed in mice challenged i.p. with viable tumor cells. Using a single prevaccination complete protection was obtained in between 40-85% of the experimental mice. When the survivors from the groups injected once with the tumor vaccine were rechallenged with viable tumor cells (101 day after the first tumor challenge, no additional prevaccination), 15.7% remained free of tumor, while the survivors from the groups injected with the tumor vaccine twice and 101 day later rechallenged with viable tumor cells remained free of tumor in 60% of the cases. Based on these results we can postulate that our vaccine is effective for prevention of tumor development. The achieved protection can be augmented with serial vaccinations and can be maintained for a longer period of time.

Bioconjugation of tumor necrosis factor-alpha with the copolymer of divinyl ether and maleic anhydride increasing its antitumor potency.

To enhance the therapeutic usefulness of antitumor cytokines in vivo, we synthesized bioconjugated tumor necrosis factor-alpha (TNF-alpha) with divinyl ether and maleic anhydride copolymer (DIVEMA), which has intrinsic antitumor activity as a synthetic biological response modifier. The degree of modification could be controlled by the addition of 2,3-dimethylmaleic anhydride (DMMAn), which binds to amino groups of TNF-alpha by changing the pH. In addition, the specific activity of DIVEMA-TNF-alpha was hardly decreased in vitro. DIVEMA-TNF-alpha showed a marked antitumor effect compared to native TNF-alpha without any side effects such as sudden death, body-weight reduction, and decrease in platelet count on mice bearing solid tumors. These results suggest that DIVEMA is a useful polymeric modifier for-bioconjugation of TNF-alpha in order to increase its antitumor activity, and multifunctionally bioconjugated TNF-alpha may be a potentiated antitumor agent for therapeutic use.

Antiviral activity of biological response modifiers in a murine model of AIDS. Requirement for augmentation of natural killer cell activity and synergy with oral AZT.

We employed the Rauscher murine leukemia virus (RMuLV) as a murine retrovirus model of AIDS, to test biological response modifiers (BRM) and antiviral agents for potential therapeutic activity against the human immunodeficiency virus (HIV). We examined the relationship between the augmentation of natural killer (NK) cell activity and antiviral efficacy of a series of BRM, most of which are known inducers of interferon, in this model. Poly [I,C]-LC, MVE-2, and CL 246,738, but not Ampligen, soluble glucan, or 7-thia-8-oxoguanosine, consistently produced antiviral activity. In addition, the combination of suboptimal doses of oral 3'-azido-3'-deoxythymidine (AZT) (in drinking water) and poly [I,C]-LC produced a synergistic antiviral effect. With all the BRM tested, a consistent pattern emerged, namely that antiviral activity always correlated with the augmentation of splenic NK cell activity in infected animals. For instance, poly [I,C]-LC boosted NK activity much more in infected mice treated therapeutically (treatment initiated after infection) than prophylactically (treatment initiated before infection), and it had greater antiviral activity therapeutically than prophylactically. For the BRM tested, antiviral activity did not occur without augmentation of NK activity in infected mice. In contrast, augmentation of NK activity in uninfected mice bore no relationship to antiviral activity. Furthermore, elimination of NK cells by treating mice with anti-asialo GM1 abolished the antiviral activity of poly [I,C]-LC. Although splenic NK activity was ablated by anti-asialo GM1, serum interferon levels were not affected by this treatment. These results point to a causal connection between the augmentation of NK cell activity and the antiviral efficacy of these BRM in this murine AIDS model. NK cells thus appear to play a key role in resistance to this retrovirus, as has been suggested for HIV.

[[Therapeutic perspectives in multiple sclerosis]. / Perspectives thérapeutiques dans la sclérose en plaques.

Numerous clinical trials have been performed during the last 5 years in multiple sclerosis patients. Some of the results have been encouraging. However, clinical benefit remains limited. Corticosteroids are indicated during the course of severe relapses but have not proven any long term benefit. Immunosuppressive agents may be of some help during very active stages of the disease. Results of interferon beta-1b trial in relapsing multiple sclerosis have shown a moderate decrease in the frequency of relapses. The same effect has recently been reported with interferon beta-1a. In addition, an effect on disability progression have been suggested with the latter interferon. In France, interferon beta-1b is now authorized in the relapsing forms of the disease. Initial results with copolymer I also suggest an effect on the frequency of relapses. Despite these major therapeutical efforts, further trials, possibly using new therapeutical approaches, are still needed.

Protection against murine cytomegalovirus infection in aged mice and mice with severe combined immunodeficiency disease with the biological response modifiers polyribosinic-polycytidylic acid stabilized with L-lysine and carboxymethylcellulose, maleic anhydride divinyl ether and colony stimulating factor 1.

A variety of biological response modifiers (BRMs) have provided antiviral protection to immunocompetent mice, and this prompted us to determine their efficacy against murine cytomegalovirus (MCMV) infection in immunocompromised mice-including the profoundly immunocompromised SCID mice and C57Bl/6 and B6D2F1 aged mice. SCID mice showed a marked decrease (> 20-fold) in resistance to MCMV, while there was a slight decrease (3-fold) in aged mice. In BRM antiviral protection studies, SCID mice were almost completely protected against MCMV infection by the pleiotropic immunomodulators, MVE-2 and pICLC, but much less by the more selective CSF-1. pICLC-induced IFN and NK cell cytotoxicity were maintained in SCID mice, suggesting that pleiotropic immunomodulatory effects may be required for antiviral protection in such a profoundly immunocompromised model. pICLC also effectively protected aged mice against lethal MCMV infection and effectively induced IFN. These results emphasize the potential for BRM treatment in immunocompromised hosts.

Effect of immunomodulators in the hu-PBL-SCID mouse model.

The effects of two immunomodulators were investigated in severe combined immunodeficient mice reconstituted with human peripheral blood lymphocytes (hu-PBL-SCID mice). Both immunomodulators, maleic anhydride divinyl ether (MVE-2) and 4-imino-1,3-diazobicyclo-(3.1.0)-hexan-2- one (imexon), have been previously studied by us in retrovirus-infected mice. To determine the effects of these compounds as they may function in humans, 24 SCID mice were each reconstituted with 20 x 10(6) ficoll-purified lymphocytes from a single donor. Five weeks after reconstitution, the mice received 16 mg/kg/day of MVE-2 intraperitoneally (i.p.) on days 0, 7, and 14 or 110 mg/kg/day of imexon i.p. daily for 14 days. Spleens were removed and splenocytes labeled with monoclonal antibodies for T- and B-cell enumeration as determined by flow cytometry 24 h after final treatment. Imexon-treated mice demonstrated a slight increase in total T cells and T cell subsets compared to control mice. T helper/T suppressor cell ratios in imexon-treated mice were brought to a normal 3:2 ratio compared to placebo-treated mice. Human immunoglobulin levels were markedly increased in imexon-treated mice. MVE-2-treated hu-PBL-SCID mice had significantly reduced numbers of total T cells compared to controls. The T-cell population results using human cells in SCID mice were similar to the effects of these immunomodulators on murine cells in immunologically competent mice.

Varying role of alpha/beta interferon in the antiviral efficacy of synthetic immunomodulators against Semliki Forest virus infection.

The question of whether interferon alpha/beta is the common mechanism of antiviral action of synthetic immunomodulators was investigated in B6C3F1 mice infected with Semliki Forest virus. Mice were treated with various concentrations of normal sheep serum or potent anti-alpha/beta interferon antiserum, inoculated with the immunomodulators, and infected 24 hours later with virus. Three patterns emerged. The antiviral action of the pyrimidinone (ABMP) and the oral interferon inducer (CL246,738) appeared to be mediated primarily by interferon alpha/beta; their protective ability was almost completely abrogated by treatment with low levels of anti-alpha/beta interferon antiserum. The antiviral action of two other immunomodulators, a mismatched polyribonucleotide (Ampligen) and a polyanionic copolymer (MVE-2) at least partially involved interferon. Activity of these compounds was reduced, but not consistently eliminated by treatments with high doses of antiserum. The antiviral activity of another polyribonucleotide, polyriboinosinic-cytidylic acid complexed with lysine carboxymethylcellulose (poly ICLC), was not affected by treatment with even the highest amount of antiserum (two injections of 100,000 neutralizing units each). Almost complete protection by poly ICLC was observed despite the fact that this high concentration of antiserum, when given alone, caused a decrease in natural resistance to Semliki Forest virus infection. Taken together, these results indicate that induction of interferon alpha/beta does not appear to be the major common mechanism of antiviral activity among these diverse synthetic immunomodulators.

[Antitumor activity of polyanion and its application for drug delivery system of antitumor drugs].

Polyanionid copolymer of divinyl ether and maleic anhydride (DIVEMA) with narrow molecular weight distribution was synthesized and tested of its antitumor activity. DIVEMA showed a significant antitumor activity against colon 26 adenocarcinoma and FSaI fibrosarcoma transplanted in syngenic mice. Furthermore, DIVEMA was used as a polymeric drug carrier of antitumor drugs to reduce side effects and enhance the antitumor activity of the drugs. Adriamycin and neocarzinostatin were attached covalently to DIVEMA and the polymeric conjugates showed higher antitumor activity than the corresponding mother drugs against P 388 leukemic mice.

Oxygen radicals in influenza-induced pathogenesis and treatment with pyran polymer-conjugated SOD.

The pathogenicity of influenza virus infection in the mice involves, at least in part, overreaction of the immune responses of the host rather than a direct effect of virus multiplication. Xanthine oxidase, which is responsible for the generation of oxygen free radicals, was elevated in serum and lung tissue of mice infected with influenza virus. To test the theory that oxygen-free radicals are involved in pathogenesis, free radicals were removed by injecting superoxide dismutase (SOD), a specific superoxide radical scavenger, which was conjugated with a pyran copolymer. The conjugate protected mice against a potentially lethal influenza virus infection if administered 5 to 8 days after infection. These findings indicate that oxygen radicals are important in the pathogenesis of influenza virus infection, and that a polymer-conjugated SOD has therapeutic potential for this virus infection and other diseases associated with free radicals.

Increased therapeutic efficacy and reduced toxicity of doxorubicin linked to pyran copolymer via the side chain of the drug.

Doxorubicin was covalently linked to divinyl ether-maleic anhydride copolymer (pyran copolymer) in its polycarboxylate form via the methylketone side chain through a nucleophilic substitution reaction of the 14-bromo derivative of the drug. The drug conjugated to the synthetic polyanionic polymer was tested for antitumor activity in a range of experimental murine tumor systems. When administered ip to mice bearing ip implanted tumors (P388 leukemia or macrophage tumor J774), the polymer-linked drug was superior to free doxorubicin and daunorubicin in increasing the life span of treated animals. Treatment with the conjugate also resulted in an improvement in survival time of mice bearing ascitic M50 tumor, although the effects of a single dose of free drug, in the range of maximum tolerated doses, were marginal. When given iv, the conjugate was more effective than free drug against systemic Gross leukemia. The therapeutic advantage of the polymer-linked doxorubicin over free drug was more marked when a multiple treatment schedule was used. Studies in vitro showed that the drug following covalent fixation to the polymer had only marginally decreased cytotoxicity against HeLa and P388 cells when compared with that of free anthracycline. This effect paralleled the lack of reduction in in vivo potency. Moreover, the covalent linkage of the drug to synthetic polymer reduced drug toxicity. This effect was more marked with the ip route of administration than with the iv route.