Resumen 16. El búfalo fue introducido en Argentina a comienzo del siglo XX, mediante la importación de razas Mediterránea, Murrah y Jafarabadi. En la actualidad la población bubalina es de 147.785 cabezas distribuidas en 19 de las 23 provincias argentinas que componen el territorio nacional. El 88 % de la población de búfalos se encuentra en el nordeste argentino, siendo las provincias de Corrientes y Formosa las que cuentan con las mayores densidades poblacionales. Existen actualmente 1193 productores de búfalos en todo el país. Las proyecciones de población bubalina para el año 2030 alcanzan la cifra de 430.000 cabezas.

Abstract 20. The buffalo was introduced in Argentina at the beginning of the 20th century, through the importation of Mediterranean, Murrah and Jafarabadi breeds. At present the buffalo population is 147,785 heads distributed in 19 of the 23 Argentine prov- inces that make up the national territory. 88% of the buffalo population is found in the north-east of Argentina, being the provinces of Corrientes and Formosa the ones with the highest population densities. There are currently 1,193 buffalo producers across the country. The buffalo population projections for the year 2030 reach the figure of 432,262.

In this work the structural requirements of both urea and thiourea derivatives were evaluated for optimal antibacterial activity on Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli, using several organic compounds (VI-X) as chemical tools. In order to delineate the structural chemical requirements of studied compounds, the descriptors Log P, p MR and MV were calculated. The results showed that bacterial growth of the studied microorganisms, in presence of IV and VI compounds was inhibited at low concentrations in comparison with I-III, V and VII-X. Other results indicate that Log P increase in II-V, VIII compounds and decrease in the VI-X substances in comparison with I thiourea-derivative. In addition, other data indicate that the p values are lower in the II-X substances in comparison with I compound. Other data showed an increase in both MR and MV values in the I-V and VIII compounds and a decrease in the VI, VII, IX and X substances. In conclusion, the results found indicate that substituents involved in the chemical structure of both urea and thiourea derivatives increase the lipophilicity and changes in the functional groups decrease the Log P. Therefore, this phenomenon can affect the antibacterial activity on Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli. In addition the results indicate that steric impediment, the molecular mechanism, conformational preferences and internal rotation of different compounds could affect the antibacterial effect of studied compounds.

En este trabajo, los requerimientos estructurales de los derivados de urea y tiourea fueron evaluados para su actividad antibacterial sobre Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli, usando varios compuestos orgánicos (VI-X) como herramientas químicas. Para delinear los requerimientos estructurales químicos de los compuestos estudiados, fueron calculados los descriptores Log P, p, MR y MV. Los resultados mostraron que el crecimiento bacterial de los microorganismos estudiados, en presencia de los compuestos IV y VI fue inhibido a bajas concentraciones en comparación con I-III, V y VII-X. Otros resultados indican que el Log P aumenta en los compuestos II-V, VIII y disminuye en las sustancias VI-X en comparación con el derivado de tiourea I. Además otros datos indican que los valores de p son menores en las sustancias II-X en comparación con el compuesto I. Otros datos, mostraron un incremento en los valores de RM y VM en los compuestos I-V, VIII y un decremento en las sustancias VI, VII, IX y X. En conclusión, los resultados encontrados indican que los sustituyentes involucrados en estructura química de los derivados de urea y tiourea incrementan la lipofilicidad y los cambios en los grupos funcionales disminuyen el log P. Por lo tanto, este fenómeno puede afectar la actividad antibacterial sobre Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli. Además, los resultados indican que el impedimento estérico, el mecanismo molecular, las preferencias conformacionales y la rotación interna de los diferentes compuestos podrían afectar su efecto antibacterial.

Background: anorectal ultrasonography (ARU) is a simple technique, and its diagnostic value for anorectal diseases either in conventional subjects or in patients with Crohn's disease (CD) is insufficiently reported. The objective of this study is to evaluate the use of ARU, its consistency with clinical orientation, and its ability to provide relevant information for patients with bowel CD and perianal involvement. Methods: thirty ARUs were performed for 24 patients (17 male, mean age 35,7 years; range 19-59 years) with diagnosed CD (bowel and anorectal involvement). The reason to perform an ARU was to evaluate an anal fistula (15 patients, 50%), potential abscesses (9 patients, 30%), and fecal incontinence (2 patients, 6,6%), and for post-treatment monitoring purposes (4 patients, 13,3%). Results: diagnostic orientation coincided for 14 patients (46,6%). An abscess was found in eight patients (26,6%), and five patients were clinically suspicious. The abscess was postanal in 3 patients. Fistulas were found in 17 patients (56,6%), and 15 patients were clinically suspicious. Transsphincterian fistulas were observed in seven patients, and abscesses were associated with fistula in six patients. Transsphincteric defects were observed in 10 patients (four internal sphincters, one external sphincter, and five both) but only two patients suffered from incontinence. ARU provided data relevant to therapeutic approach in 19 patients (63,3%). Conclusions: ARU has provided very important data for the diagnosis and treatment of anorectal diseases. Based on this technique clinical decisions can be improved, which in some instances may prove critical.

Introduction: Severe Bordetella pertussis infection in infancy is associated with high mortality, in spite of vital advanced support. Refractory pulmonary hypertension (PHT) is a bad prognostic condition associated, whose etiology is poorly understood. Hyperleukocytosis is an identified risk factor for PHT, in which the use of techniques to reduce the leukocyte mass such as exchange transfusion is suggested. Case report: A 4 months-old girl not vaccinated before, with severe Pertussis developing respiratory and myocardial failure, with severe PHT and a leukocyte count of 78800/UL. After conventional therapy failed, we used exchange transfusion showing respiratory and hemodynamic improvement temporally. We suggest that early exchange transfusion in severe Pertussis with hyperleukocytosis is an efficient therapy

Introducción: La infección grave causada por Bordetella pertussis en la infancia produce una alta mortalidad, a pesar del uso de soporte vital avanzado. Su mal pronóstico está ligado al desarrollo de hipertensión pulmonar refractaria, cuya etiopatogenia es pobremente entendida. La presencia de hiperleucocitosis en estos niños es un factor de riesgo conocido para la génesis de hipertensión pulmonar, sugiriéndose recientemente el empleo de terapias cito reductoras, entre ellas la exanguineotransfusión. Caso clínico: Comunicamos una lactante de 4 meses de edad, no vacunada que ingresa por coqueluche, con marcado compromiso de intercambio gaseoso, shock cardiogénico e hipertensión pulmonar grave asociados a leucocitosis de 78,800/µl. Ante fracaso de la terapia habitual se decide realizar exanguineotransfusiones, obteniéndose una buena respuesta hemodinámica y de intercambio gaseoso, temporalmente asociadas a la terapia, inexplicable por el curso natural de la enfermedad. Conclusión: El caso presentado sugiere que la exanguineotransfusión precoz puede ser una terapia útil en el tratamiento del coqueluche grave con hiperleucocitosis

Anopheles (Nyssorhynchus) aquasalis, is the main coastal vector of malaria from northeastern Venezuela to southeastern Brazil. Several authors have argued that An. aquasalis is a highly polymorphic species while others indicated that it is a complex of closely related species. This investigation compared the morphology of An. aquasalis eggs from Sinamaica (Zulia State) and Yaguaraparo (Sucre State), the west and east of Venezuela, respectively. We were able to separate eggs from the two localities using discriminant analyses based on ratios and percentages of anterior and posterior tubercles measured by scanning electron microscopy. The results of this work suggest that An. aquasalis has high intraspecific variation