[Surgical treatment of tracheal stenosis. A 11-year report in a pediatric hospital]. / Tratamiento quirúrgico de la estenosis traqueal. Reporte de 11 años en un hospital pediátrico.

OBJECTIVES: To report our experience in the surgical treatment of patients having acquired and congenital tracheal stenosis. MATERIAL AND METHODS: Fifty eight patients with tracheal stenosis were surgically treated between July 2005 and May 2016, 29 were females and 29 were males. Thirty patients had acquired stenosis and 28 had congenital stenosis. RESULTS: Five to 12 rings were resected (median 5) in 26 patients, in 2 cartilage was grafted in the anterior wall, in another carinostomy was performed, and in the remaining, the trachea was replaced using an aortic cryopreserved graft. In those with congenital stenosis, 14 patients underwent slide technique; in eleven, 3 to 6 rings were resected (median 5); in 3 a patch was grafted in the anterior tracheal wall. Seven patients died: 2 with acquired stenosis and 5 with congenital stenosis. Global survival was 88% (28 of 30 patients with acquired stenosis and 23 of 28 with congenital). From 28 living patients operated on due to acquired stenosis, 26 are asymptomatic, one presents graft stenosis, and one has a stoma in the aortic graft. From 23 living patients operated on due to congenital stenosis, 20 remain asymptomatic and 3 have tracheal stents placed on. CONCLUSIONS: Surgical treatment of acquired stenosis is easier and presents less severe complications. Congenital stenosis often requires more than one procedure to control the disease, and presents a higher mortality rate.

OBJETIVOS: Describir nuestra experiencia en el tratamiento quirúrgico de pacientes con estenosis traqueal adquirida y congénita. MATERIAL Y METODOS: Cincuenta y ocho pacientes con estenosis de tráquea fueron intervenidos quirúrgicamente entre julio de 2005 y mayo de 2016, 29 eran de sexo femenino y 29 de sexo masculino. Treinta pacientes tenían una estenosis de origen adquirido y 28 de origen congénito. RESULTADOS: Fueron resecados entre 5 y 12 anillos (mediana 5) en 26 pacientes con estenosis adquirida, en 2 se efectuó injerto de cartílago en cara anterior, en 1 carinostomía, y en el restante (a este paciente se le había realizado previamente una resección laringotraqueal) se efectuó un reemplazo traqueal con aorta criopreservada. De los veintiocho pacientes con estenosis congénita, en 14 se empleó la técnica de deslizamiento, en 11 se resecaron entre 3 y 6 anillos (mediana 5), y en 3 se colocó un injerto en cara anterior de la tráquea. Fallecieron 7 pacientes: 2 con estenosis adquirida y 5 con estenosis congénita. La supervivencia global fue del 88% (28 de 30 pacientes con estenosis adquirida y 23 de 28 con congénita). De los 28 pacientes vivos operados por estenosis adquirida, 26 se encuentran asintomáticos, uno presenta estenosis del injerto y otro tiene un estoma en el injerto de aorta. De los 23 pacientes vivos operados por estenosis congénita, 20 se encuentran asintomáticos y 3 tienen endoprótesis colocadas. CONCLUSIONES: En nuestra experiencia, la resolución quirúrgica de la estenosis traqueal adquirida resultó más sencilla y presentó menos complicaciones. Los pacientes con estenosis traqueal congénita necesitaron generalmente más de un procedimiento para el control de su sintomatología, y presentaron mayor mortalidad.

Tratamiento quirúrgico de la estenosis traqueal. Reporte de 11 años en un hospital pediátrico / Surgical treatment of tracheal stenosis. A 11-year report in a pediatric hospital

Objetivos. Describir nuestra experiencia en el tratamiento quirúrgico de pacientes con estenosis traqueal adquirida y congénita. Material y métodos. Cincuenta y ocho pacientes con estenosis de tráquea fueron intervenidos quirúrgicamente entre julio de 2005 y mayo de 2016, 29 eran de sexo femenino y 29 de sexo masculino. Treinta pacientes tenían una estenosis de origen adquirido y 28 de origen congénito. Resultados. Fueron resecados entre 5 y 12 anillos (mediana 5) en 26 pacientes con estenosis adquirida, en 2 se efectuó injerto de cartílago en cara anterior, en 1 carinostomía, y en el restante (a este paciente se le había realizado previamente una resección laringotraqueal) se efectuó un reemplazo traqueal con aorta criopreservada. De los veintiocho pacientes con estenosis congénita, en 14 se empleó la técnica de deslizamiento, en 11 se resecaron entre 3 y 6 anillos (mediana 5), y en 3 se colocó un injerto en cara anterior de la tráquea. Fallecieron 7 pacientes: 2 con estenosis adquirida y 5 con estenosis congénita. La supervivencia global fue del 88% (28 de 30 pacientes con estenosis adquirida y 23 de 28 con congénita). De los 28 pacientes vivos operados por estenosis adquirida, 26 se encuentran asintomáticos, uno presenta estenosis del injerto y otro tiene un estoma en el injerto de aorta. De los 23 pacientes vivos operados por estenosis congénita, 20 se encuentran asintomáticos y 3 tienen endoprótesis colocadas. Conclusiones. En nuestra experiencia, la resolución quirúrgica de la estenosis traqueal adquirida resultó más sencilla y presentó menos complicaciones. Los pacientes con estenosis traqueal congénita necesitaron generalmente más de un procedimiento para el control de su sintomatología, y presentaron mayor mortalidad (AU)

Objectives. To report our experience in the surgical treatment of patients having acquired and congenital tracheal stenosis. Material and methods. Fifty eight patients with tracheal stenosis were surgically treated between July 2005 and May 2016, 29 were females and 29 were males. Thirty patients had acquired stenosis and 28 had congenital stenosis. Results. Five to 12 rings were resected (median 5) in 26 patients, in 2 cartilage was grafted in the anterior wall, in another carinostomy was performed, and in the remaining, the trachea was replaced using an aortic cryopreserved graft. In those with congenital stenosis, 14 patients underwent slide technique; in eleven, 3 to 6 rings were resected (median 5); in 3 a patch was grafted in the anterior tracheal wall. Seven patients died: 2 with acquired stenosis and 5 with congenital stenosis. Global survival was 88% (28 of 30 patients with acquired stenosis and 23 of 28 with congenital). From 28 living patients operated on due to acquired stenosis, 26 are asymptomatic, one presents graft stenosis, and one has a stoma in the aortic graft. From 23 living patients operated on due to congenital stenosis, 20 remain asymptomatic and 3 have tracheal stents placed on. Conclusions. Surgical treatment of acquired stenosis is easier and presents less severe complications. Congenital stenosis often requires more than one procedure to control the disease, and presents a higher mortality rate (AU)

Optimización de un método de PCR en tiempo real para el diagnóstico de infecciones por Mycoplasma pneumoniae / Optimization of a real-time PCR method for the diagnosis of Mycoplasma pneumoniae infections

A Mycoplasma pneumoniae se lo ha descrito como causante de diversas patologías, pero la más frecuente es la neumonía de la comunidad, en la que puede asociarse a otros patógenos. Afecta pincipalmente a niños de edad escolar y adultos jóvenes, aunque en las últimas décadas es frecuente hallarlo también en niños menores de 5 años. El daño celular ocurre sobre el epitelio de bronquios y bronquiolos por acumulación de peróxido de hidrógeno y radicales superóxido producidos durante su metabolismo celular. Recientemente se ha reportado que en estos eventos patogénicos también participa una citotoxina conocida como CARDS toxin (community-acquired respiratory distress syndrome) que la bacteria expresa como factor de virulencia, ya que induce una importante respuesta inflamatoria celular. Los métodos moleculares son más sensibles y rápidos que los métodos de diagnóstico tradicionales y se consideran de elección. No obstante, para lograr un diagnóstico óptimo, se aconseja la combinación de estos métodos junto con los serológicos. En el presente estudio se optimiza un método de PCR en tiempo real con iniciadores dirigidos a la región del gen que codifica la CARDS toxin. El método demostró ser muy sensible y rápido para el diagnóstico clínico de M. pneumoniae, con una concordancia қ: 0,95 con el método convencional de PCR anidada que emplea como target al gen que codifica para la citoadhesina P1. A su vez es mucho menos laborioso e implica un menor riesgo de contaminación, lo que permite el manejo de un alto número de muestras clínicas (AU)

Mycoplasma pneumoniae has been described as the cause of different infections, the most common of which is communityacquired pneumonia, possibly associated with other pathogens. Community-acquired pneumonia mainly affects school-age children and young adults, although over the past decades the disease has also been found in children under 5 years of age. Cell damage occurs on the epithelium of the bronchi and bronchioles due to accumulation of hydrogenous peroxide and superoxide radicals produced during cell metabolism. Recently, it has been reported that in these pathogenic events a cytotoxin known as CARDS toxin (community-acquired respiratory distress syndrome) participates, expressed by the bacteria as a factor of virulence, as it induces an important inflammatory cell response. The molecular methods are more sensitive and faster than the traditional diagnostic methods, and are considered the methods of choice; however, for an optimal diagnosis, a combination of these methods together with serological studies is recommended. In the current study, a real-time PCR method with markers targeted to the region of the gene encoding the CARDS toxin was optimized. The method showed to be very sensitive and fast for the clinical diagnosis of M. pneumoniae, with a қ agreement of 0.95 with the conventional nested PCR method that uses the gene encoding cytoadhesin P1 as a target. Additionally, the new method is much easier with a lower risk of contamination, which allows management of a large number of clinical samples (AU)

Compromiso renal de los pacientes con tumor de Wilms bilateral / Kidney involvement in patients with bilateral Wilms tumor

El tumor de Wilms (TW) es el tumor renal maligno más frecuente en la infancia. Entre el 5-7% de los pacientes se presentan con enfermedad TW bilateral, de forma sincrónica o metacrónica. El TW bilateral generalmente ocurre en pacientes pequeños y más frecuentemente en niñas. La cirugía es un componente crítico en el tratamiento para lograr una alta tasa de curación preservando la mayor cantidad de masa renal. La quimioterapia preoperatoria a menudo reduce significativamente el tamaño del tumor, facilitando la cirugía posterior. Los pacientes con TW bilateral deben ser tratados en centros con experiencia en esta patología. El manejo de estos pacientes es aún un desafío (AU)

Wilms tumor (WT) is the most common malignant kidney tumor in childhood. Between 5-7% of the patients present with synchronous or metachronous bilateral WT. Bilateral WT typically occurs in young patients and most frequently in girls. Surgery is a critical component of the treatment as it has a high rate of cure while preserving the largest kidney mass. Preoperative chemotherapy often significantly reduces the size of the tumor, facilitating subsequent surgery. Patients with bilateral WT should be managed at centers with experience treating this disease. The management of these patients is still a challenge (AU)

[Myofibroblastic tumor of the lung: clinical features and results in 9 children]. / Tumor miofibroblástico de pulmón: aspectos clínicos y resultados en 9 niños.

INTRODUCTION: Primary lung tumors in children are rare, being the myofibroblastic lung tumor (MLT) reported as the most common. Nevertheless the literature about it is scarce, and mostly consistent of case reports. The aim of this article is to describe the results obtained in a group of patients with this tumor treated in a tertiary pediatric hospital. METHODS: A single institution retrospective chart review was performed with institutional review board approval. All patients treated between 1990 and 2010 with diagnosis of MLT were included. Age, symptoms at presentation, surgical procedures, complications, histopathology and follow-up were reviewed. RESULTS: 9 patients were identified. The commonest symptoms at presentation were fever and cough (n=6), and seizures (n=2). Surgical treatment consisted in complete resection in 8 patients and partial resection in 1. To achieve this 3 patients underwent pneumonectomy and 6 lobectomy. Two of the patients with pneumonectomy required also a partial resection of the right atrium and both had cerebral lesions. The mean follow-up was 2.8 years (r:0.16-12) and all the patients that remained in follow-up (66%) are alive at the moment. DISCUSSION: Complete surgical resection in MLT is possible, however, to achieve this complex procedures and a multidisciplinary approach might be needed. Although the potential of distant metastasis is not clearly reported, we think that it is a topic that must be carefully revised.

Tumor miofibroblástico de pulmón: aspectos clínicos y resultados en 9 niños / Myofibroblastic tumor of the lung: clinical features and results in 9 children

Introducción. El tumor miofibroblástico (TMF) está descrito como el tumor primario de pulmón más frecuente en pediatría. Sin embargo, la literatura al respecto es escasa y en su mayoría consiste en reportes de casos. Nuestro objetivo es describir los resultados obtenidos en un grupo de pacientes con este tipo de tumor tratados en un hospital pediátrico de derivación en 20 años. Material y métodos. Se realizó una revisión retrospectiva de las historias clínicas de niños tratados entre 1990 y 2010 con diagnóstico de TMF de pulmón. Se registraron edad, síntomas al momento del diagnóstico, tratamiento quirúrgico, complicaciones peri y postoperatorias, análisis histopatológico y evolución clínica. Resultados. Fueron intervenidos en nuestra institución 9 pacientes con diagnóstico de TMF con una relación varón/mujer de 1,25:1. Las presentaciones más frecuentes fueron tos y fiebre (n=6) y convulsiones(n=2). El tratamiento realizado consistió en la resección quirúrgica completa en 8 e incompleta en 1. Para lograrlo se realizaron 3 neumonectomías y 6 lobectomías. Dos de los pacientes neumonectomizados requirieron resección parcial de aurícula izquierda y ambos pacientes presentaron metástasis cerebrales. El seguimiento promedio fue de 2,8años (r:0,16-12) y todos los pacientes que continúan en control (66%)se encuentran vivos en el momento del estudio. Discusión. La resección quirúrgica completa de los TMF de pulmónes posible, si bien puede requerir cirugías complejas y un abordaje multidisciplinario. Si bien la diseminación a distancia no está claramente descrita, creemos que es un tema que debe ser cuidadosamente revisado (AU)

Introduction. Primary lung tumors in children are rare, being themyofibroblastic lung tumor (MLT) reported as the most common. Nevertheless the literature about it is scarce, and mostly consistent of case reports. The aim of this article is to describe the results obtained in a group of patients with this tumor treated in a tertiary pediatric hospital. Methods. A single institution retrospective chart review was performed with institutional review board approval. All patients treated between 1990 and 2010 with diagnosis of MLT were included. Age, symptoms at presentation, surgical procedures, complications, histopathology and follow-up were reviewed. Results. 9 patients were identified. The commonest symptoms at presentation were fever and cough (n=6), and seizures (n=2). Surgical treatment consisted in complete resection in 8 patients and partial resection in 1. To achieve this 3 patients underwent pneumonectomy and 6 lobectomy. Two of the patients with pneumonectomy required also a partial resection of the right atrium and both had cerebral lesions. The mean follow-up was 2.8 years (r:0.16-12) and all the patients thatremained in follow-up (66%) are alive at the moment. Discussion. Complete surgical resection in MLT is possible, however, to achieve this complex procedures and a multidisciplinary approach might be needed. Although the potential of distant metastasis is not clearly reported,we think that it is a topic that must be carefully revised (AU)

Apoptosis en trasplante de pulmón. Influencia del lavado y la reperfusión del órgano / Apoptosis in lung transplantation. Influence of lavage and reperfusion on the organ

Objetivo: Determinar el rol de la irrigación con soluciones de preservación, la reperfusión y el rechazo en la apoptosis pulmonar en un escenario de trasplante pulmonar. Material y método: Venticuatro cerdos Landrace con un peso de 15 a 30 kilogramos fueron usados como donantes y receptores en un modelo de trasplante pulmonar izquierdo, con 5 días de sobrevida. Las muestras se obtuvieron en la siguiente secuencia: 1A: Donante, pulmón izquierdo inmediatamente luego de la apertura del torax. 1B: donante, pulmón derecho, inmediatamente luego de la apertura del tórax. 2A: Donante pulmón izquierdo, inmediatamente luego de la irrigación del organo. 2B Donante, pulmón derecho, sin irrigar. 3A: Pulmón izquierdo implantado, 1 hora luego de reperfundido en el receptor . 3B: Pulmón derecho (nativo), 1 hora luego de reperfundido el pulmón donante en el receptor. 4A: Pulmón izquierdo, biopsia transbronquial a las 48 horas postrasplante. 4B: Pulmón derecho, biopsia transbronquial a las 48 horas postransplante. 5A: Púlmón izquierdo, 5º día postrasplante (sacrificio). Todos los pulmones fueron irrigados con solución de Euro-Collins fría (4Cº) durante la ablación. Seis receptores no recibieron inmunosupresión y otros 6 receptores recibieron 15 mg/KG/ día de ciclosporina intravenosa. Los niveles plasmáticos de ciclosporina fueron dosados en tiempo 0 al 2º y 5º día postrasplante. Cada muestra fue analizada por un observador ciego para determinar el grado de rechazo (A0 y A1 negativo. A2. A3 y A4 positivo), proliferación celular, y el índice de apaptosis en neumonocitos I y II empleando la técnica de TUNEL y Caspasa. Las pruebas de Chi cuadrado; prueba de t de student y kruskal Wallis fueron utilizadas para el análisis estadístico. Se consideró significativo un valor de p menor a 0.05. Resultados: El grado de rechazo fue negativo en todas las muestras excepto en 4A (1 animal) y 5A (5 animales sin ciclosporina y 3 animales de los que recibieron ciclosporina) (p<0.05)

Apoptosis en trasplante de pulmón / Apoptosis in lung transplantation. Influence of lavage and reperfusion on the organ

Objetivo: Determinar el rol de la irrigación con soluciones de preservación, la reperfusión y el rechazo en la apoptosis pulmonar en un escenario de trasplante pulmonar. Material y método: Venticuatro cerdos Landrace con un peso de 15 a 30 kilogramos fueron usados como donantes y receptores en un modelo de trasplante pulmonar izquierdo, con 5 días de sobrevida. Las muestras se obtuvieron en la siguiente secuencia: 1A: Donante, pulmón izquierdo inmediatamente luego de la apertura del torax. 1B: donante, pulmón derecho, inmediatamente luego de la apertura del tórax. 2A: Donante pulmón izquierdo, inmediatamente luego de la irrigación del organo. 2B Donante, pulmón derecho, sin irrigar. 3A: Pulmón izquierdo implantado, 1 hora luego de reperfundido en el receptor . 3B: Pulmón derecho (nativo), 1 hora luego de reperfundido el pulmón donante en el receptor. 4A: Pulmón izquierdo, biopsia transbronquial a las 48 horas postrasplante. 4B: Pulmón derecho, biopsia transbronquial a las 48 horas postransplante. 5A: Púlmón izquierdo, 5º día postrasplante (sacrificio). Todos los pulmones fueron irrigados con solución de Euro-Collins fría (4Cº) durante la ablación. Seis receptores no recibieron inmunosupresión y otros 6 receptores recibieron 15 mg/KG/ día de ciclosporina intravenosa.

Surveillance of adamantane resistance among influenza A H3 viruses isolated in Argentina between 2001 and 2007.

A dramatic rise in the frequency of resistance to adamantane drugs by influenza A H3 viruses, associated with a single amino acid replacement in the viral matrix M2 protein, has occurred in multiple countries worldwide in recent years. We investigated the frequency of adamantane-resistant influenza A H3 viruses in Argentina during the period 2001-2007. We used reverse transcription followed by polymerase chain reaction. The obtained products were sequenced for the detection of mutations of the M2 gere relevant to the resistance phenotypes. The HA1 sequences of the sensitive and resistant strains were also analyzed to clarify whether they had any relevance to the resistant mutations. Twenty out of 55 (36%) strains were identified with the resistance-conferring substitution at amino acid 31 (Serine 31 Asparagine). No resistant viruses were detected between 2001 and 2005. All strains isolated in 2006 and four out of five isolates from 2007 were resistant. None of the patients had received previous treatment with amantadine and/or rimantadine. The HA1 analysis showed that there were only two changes (Serine193 Phenylalanine and Aspartic acid 225 Asparagine) present in the strains with the M2 substitution at position 31. Our data indicate that since 2006 there has been a significant increase of adamantane-resistant influenza A H3 viruses, which raises concern over the spread of these viruses in Argentina.

Surveillance of adamantane resistance among influenza A H3 viruses isolated in Argentina between 2001 and 2007 / Vigilancia de la resistencia a los adamantanos entre los virus influenza A H3 aislados en Argentina entre 2001 y 2007

A dramatic rise in the frequency of resistance to adamantane drugs by influenza A H3 viruses, associated with a single amino acid replacement in the viral matrix M2 protein, has occurred in multiple countries worldwide in recent years. We investigated the frequency of adamantane-resistant influenza A H3 viruses in Argentina during the period 2001- 2007. We used reverse transcription followed by polymerase chain reaction. The obtained products were sequenced for the detection of mutations of the M2 gene relevant to the resistance phenotypes. The HA1 sequences of the sensitive and resistant strains were also analyzed to clarify whether they had any relevance to the resistant mutations. Twenty out of 55 (36%) strains were identified with the resistance-conferring substitution at amino acid 31 (Serine 31 Asparagine). No resistant viruses were detected between 2001 and 2005. All strains isolated in 2006 and four out of five isolates from 2007 were resistant. None of the patients had received previous treatment with amantadine and/or rimantadine. The HA1 analysis showed that there were only two changes (Serine193 Phenylalanine and Aspartic acid 225 Asparagine) present in the strains with the M2 substitution at position 31. Our data indicate that since 2006 there has been a significant increase of adamantane-resistant influenza A H3 viruses, which raises concern over the spread of these viruses in Argentina.

En los últimos años, se ha detectado un aumento de virus influenza A H3 resistentes a los adamantanos en distintos países, asociados mayoritariamente con el reemplazo de un único aminoácido de la proteína matriz M2. Se investigó la frecuencia de virus influenza A H3 resistentes a los adamantanos en Argentina entre 2001 y 2007. Se utilizó la transcripción reversa seguida de la reacción en cadena de la polimerasa y de la técnica de secuencia directa para la detección de mutaciones en el gen que codifica para la proteína M2, relevantes para los fenotipos de resistencia. También se analizó la secuencia de la porción HA1 de cepas resistentes y sensibles, para intentar establecer alguna relación con las mutaciones de M2. De un total de 55 cepas, 20 (36%) fueron resistentes debido a un cambio aminoacídico en la posición 31 (serina 31 asparagina). No se detectaron cepas resistentes entre 2001 y 2005. Las cepas aisladas en el 2006 y 4 de 5 cepas obtenidas en el 2007 fueron resistentes. Ninguno de los pacientes de los que se habían aislado esas cepas había recibido tratamiento antiviral con anterioridad. En la porción secuenciada de HA1 se encontraron dos cambios (serina 193 fenilalanina y ácido aspártico 225 asparagina), presentes sólo en las cepas que tuvieron la mutación en la posición 31 de M2. Desde el año 2006 se ha registrado en Argentina un aumento significativo de la circulación de virus influenza A H3 con genotipo resistente, lo que genera expectativa con respecto a su diseminación en nuestro país.

Influenza circulating strains in Argentina exhibit differential induction of cytotoxicity and caspase-3 in vitro.

BACKGROUND: Human influenza infections are a significant cause of morbidity worldwide. Though damage to the respiratory epithelium and has been related to apoptosis, which occurs subsequent to influenza virus infection, little information is available regarding cell cytotoxicity of human strains. OBJECTIVE: To study cytotoxicity performed in vitro by various circulating strains in Argentina. The study sample consisted of three vaccine strains (H1N1, H3N2, and B) administered during 1999-2000 in South America and three strains isolated from clinical samples, one, NAC (H1N1) obtained from an adult inpatient with human pneumonia; and the other two (T) and (T2) (H3N2) with influenza syndrome. Viral antigen was detected by an immunofluorescence test, conducted prior to viral isolation in MDCK cells. Strains were subtyped by the hemmaglutination inhibition test. Cytotoxic properties were determined by lactate dehydrogenase reaction (LDH), crystal violet staining and Hoechst staining. Caspase-3 activity, morphological changes of apoptosis, and viral yields were measured in MDCK infected cells. RESULTS AND CONCLUSIONS: Cells infected by each of the strains exhibited apoptosis morphology by Hoechst staining and caspase-3 activity was high for both H1N1 strains. Further, high levels of LDH activity were detected for NAC and H3N2 strains tested, indicating the possible role of different viral proteins or functions on cell cytotoxicity. The NAC strain, isolated from human pneumonia and antigenically related to A/New Caledonia /20/99 (H1N1), was the highest cytotoxic strain and an excellent inducer of caspase-3 activity. In turn, no parameter was related to different viral yields. We conclude that human strains studied in this paper may be useful tools in the characterization of molecular determinants involved in viral cytopathogenicity.

Insulin-like growth factor-I and insulin-like growth factor binding protein-2 and -5 in equine seminal plasma: association with sperm characteristics and fertility.

The objectives of this study were 1) to determine whether insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding proteins (IGFBPs) were present in seminal plasma of stallions; 2) to compare semen parameters (IGF proteins, sperm numbers, morphology, and motility) from stallions at sexual rest (SR) and when sexually active (SA); 3) to compare semen parameters between stallions with high and low seminal plasma IGF-I concentrations; and 4) to examine the relationship between seminal plasma IGF-I concentrations and fertility parameters of stallions. Ejaculates were collected from stallions at SR (n = 51) and SA (n = 46). Concentrations of IGF-I and IGFBP-2 in seminal plasma samples were determined by radioimmunoassay. Presence of IGFBPs in equine seminal plasma was verified using immunoprecipitation and Western ligand blot procedures. IGF-I, IGFBP-2, and IGFBP-5 were present in equine seminal plasma. Concentrations of IGF-I, IGF-I/protein, total IGF-I, IGFBP-2, IGFBP-2/protein, and total IGFBP-2 were not significantly different (P > or = 0.13) in seminal plasma between stallions at either SR or SA. At SR, stallions with higher seminal plasma IGF-I had more total IGFBP-2 per ejaculate (P < 0.01), more morphologically normal sperm (P = 0.05), and higher first-cycle pregnancy rates (P = 0.02). At SA, stallions with higher seminal plasma IGF-I had fewer cycles per pregnancy (P = 0.02). An association of seminal plasma IGF-I concentration with sperm motility, sperm morphology, and pregnancy rates in bred mares suggests that IGF-I may play a role in sperm function.

Interactions of xylazine and acepromazine with oxytocin and the effects of these interactions on intrauterine pressure in normal mares and mares with delayed uterine clearance.

The effects of the sedatives xylazine (predominantly alpha2 agonist) and acepromazine (predominantly alpha1 antagonist) and their influence on intrauterine pressure were measured in four reproductively normal mares and four mares with delayed uterine clearance. Intrauterine pressure was measured in each mare during oestrus for three 100 min periods using an 8-F catheter with three discrete pressure sensors. After 10 min of baseline recording, xylazine, acepromazine or saline was administered i.v. Oxytocin was administered i.v. after a further 30 min, and pressure recordings were continued for 60 min. The pressure changes analysed were: number of uterine contractions; time of onset and duration of the first contraction; and the time at which intrauterine pressure changed from baseline. Data were analysed using the mixed procedure of the Statistical Analysis System. ANOVA detected an effect of treatment (P < 0.0001) and a treatment by group interaction (P < 0.001). Xylazine administration caused a tetanic contraction in all mares. When mares with delayed uterine clearance were sedated with xylazine before administration of oxytocin, the duration of increased intrauterine pressure was longer than that of normal mares (24.87 +/- 2.52 and 15.81 +/- 2.46, respectively; P < 0.0001). Acepromazine administration had no effect on the oxytocin-induced contraction pattern in normal mares, but there was a decrease in the number of contractions in mares with delayed uterine clearance. The enhanced response to alpha-agonists and -antagonists observed in mares with delayed uterine clearance when the drugs were administered before oxytocin may be due to denervation supersensitivity. After mating, sedation of mares with xylazine is preferred to sedation with acepromazine, as xylazine increases uterine contraction time.

Dynamics of prostaglandin secretion, intrauterine fluid and uterine clearance in reproductively normal mares and mares with delayed uterine clearance.

Two experiments were performed to investigate relationships between oxytocin, prostaglandin release, uterine emptying and fluid accumulation in the uterus. In Experiment 1, the effect of oxytocin on the pattern of prostaglandin release during uterine clearance of radiocolloid was measured in 5 normal mares and 5 mares with delayed uterine clearance. Uterine clearance was measured during estrus by scintigraphy at 0, 60 and 120 min after colloid infusion. After the 120-min reading, 20 IU, i.v., oxytocin were given, and the amount of colloid cleared was measured at 135, 150 and 180 min. Plasma was obtained prior to and during scintigraphy at 5- and 15-min intervals to measure concentrations of 15-keto-13,14-dihydro-PGF2 alpha metabolite (PGFM) by RIA. In Experiment 2, plasma PGFM levels were compared after administration of oxytocin in 8 normal mares and 6 mares with delayed uterine clearance to determine if intrauterine fluid stimulated prostaglandin release. Mares received 2 treatments in a cross-over design. Treatment 1 consisted of 20 IU, i.v., oxytocin during estrus. Treatment 2 consisted of an infusion of 10 mL, i.u., saline 15 min prior to oxytocin administration. Treatments were performed 4 to 6 h apart. Blood was collected and PGFM was measured as in experiment 1. Data were analyzed by least squares analysis of variance. In Experiment 1, regression analysis of scintigraphy and PGFM profiles indicated that time response curves differed between groups (P < 0.01). At 120 min, normal mares retained 40.4 +/- 4.9% (mean +/- SEM) of the radiocolloid while mares with delayed clearance retained 88 +/- 5%. Fifteen minutes after oxytocin administration (135 min), all normal mares and 4 of 5 mares with delayed clearance retained only < 6% of the colloid. During the first 120 min, plasma PGFM concentrations did not differ between the 2 groups. After oxytocin was given, plasma PGFM concentrations increased in 4 of 5 mares with delayed uterine clearance (80 to 3,096 pg/mL) but not in normal mares (13 to 46 pg/mL). In Experiment 2, plasma PGFM concentrations did not rise in normal mares but rose in 3 of 6 mares with delayed clearance (135 to 483 pg/mL) independent of treatment or period. The results suggest that intrauterine clearance of radiocolloid after oxytocin administration appears to be independent of PGF2 alpha release in normal mares during estrus. The difference in prostaglandin release response after oxytocin administration between the 2 groups was unrelated to the presence of intrauterine fluid.

Changes in intrauterine pressure after oxytocin administration in reproductively normal mares and in those with a delay in uterine clearance.

Intrauterine pressure was measured in 4 reproductively normal mares and 4 mares with delay in uterine clearance after administration of oxytocin to determine if intrauterine pressure varied between dosage and group. Changes in intrauterine pressure were measured during estrus, when a follicle was > or =35 mm, using a Millar "Mikro-tip" catheter that had 3 discrete pressure sensors/channels. Mares received 4 different treatments of 10, 5, 2.5 or 0 IU (vehicle) of oxytocin. The protocol for each treatment consisted of a 10-min baseline recording, administration of treatment and measurement of changes in intrauterine pressure for 65 min. After administration of the first two treatments, mares were rested for 2 h and the protocol repeated for the remaining 2 treatments. Changes in intrauterine pressure were measured on a physiograph and stored in a computer. The results were analyzed by 4x4 Latin Square Design analysis of variance (ANOVA) using the GLM procedure of the Statistical Analysis System. The ANOVA detected a main effect of treatment (P<0.01) and mare (nested within group; P<0.01) but no effect of channels, group or treatment-by-group interaction. There was a dose-dependent increase in uterine activity in both normal mares and those with delayed uterine clearance. A dose of 10 IU of oxytocin induced a larger number of uterine contractions (5.67+/-0.06) for a longer time (24.09+/-1.18 min) than the 5 IU (4.16+/-0.06 contractions and 16.31+/-1.18; P<0.01 min) or 2.5 IU dose (4.08+/-0.06 contractions and 17.61+/-1.18 min). The first intrauterine wave occurred most often near the tip of the horn in 10 of 12 recordings in normal mares and in 8 of 12 recordings in mares with delayed uterine clearance. It was then propagated from the middle of the horn to the uterine body just cranial to the cervix. There was no pattern of propagation for subsequent intrauterine pressure waves. We conclude that the difference in spontaneous clearance of the uterus between the 2 groups is not reflected in their response to exogenous oxytocin as determined by changes in intrauterine pressure.