Impact of natural control agents of the citrus leafminer Phyllocnistis citrella on lemon trees varies among seasons.

Studies on insect natural enemies and their effects on host populations are of immense practical value in pest management. Predation and parasitism on a citrus pest, the leafminer Phyllocnistis citrella Stainton, were evaluated by sampling over 3 years in four locations within a world leading lemon producing area in Northwest Argentina. Both mortality factors showed seasonal trends consistent across locations, with predation exerting earlier and more sustained pressure than parasitism, which showed wider seasonal variations. The dominant parasitoids, native Cirrospilus neotropicus and introduced Ageniaspis citricola, showed different seasonal trends: C. neotropicus was dominant in spring whereas A. citricola superseded it in autumn and winter. Although parasitism rates were relatively low, the native C. neotropicus revealed favourable features as potential control agent, by showing density-dependence, parasitism rates comparable with those of the specific A. citricola during part of the cycle, and earlier synchronization with the host. The study provides highly relevant information for a sustainable management of this worldwide pest, for which biological control is considered the best long-term option.

Scanning electron microscopy of superficial defects in Twisted files and Reciproc nickel-titanium files after use in extracted molars.

AIM: To evaluate the usage and superficial defects in size 25, 0.08 taper Twisted files (TF) and R25 Reciproc files after root canal instrumentation. METHODOLOGY: One hundred and twenty mandibular molars with root canal curvature, ranging from 15° to 30° and a 4-5 mm radius, were randomly divided into two groups according to single-file instrumentation: size 25, 0.08 taper TF or R25 files. A total of fifteen files per group were evaluated before and after three, six, nine and 12 uses. The instruments were fixed in custom-made holders and photographed using scanning electron microscopy at ×260 to ×1200 magnifications. The presence of superficial defects (plastic deformation, microcracks, fracture, craters, disruption of the cutting edges and blunt edges) was scored from the pre- and post-usage photographs. Chi-squared test was used to analyse differences after usages in both groups individually. Two-way anova was used to analyse differences between both instruments. The level of significance for all analyses was 5%. RESULTS: Superficial defects were observed after the instrumentation of six root canals in the TF group and after the instrumentation of nine root canals in the R25 group. Plastic deformation and disruption of cutting edges were the prevalent defects observed in the TF group, and craters and blunt edges were observed in R25 files. The presence of defects was significantly increased with successive usages in both groups (P < 0.05), but TF had more superficial defects than R25 files (P < 0.001). Dentine debris was observed on all instruments. No instruments fractured. CONCLUSIONS: Instrumentation was possible for six root canals with TF files and nine root canals with R25 files before the presence of superficial defects appeared. Differences in the prevalence and development of superficial defects were observed between the TF and R25 files.

Spatial and temporal variation in Chaetanaphothrips orchidii Moulton (Thysanoptera: Thripidae) population and its damage on lemon.

Chaetanaphothrips orchidii Moulton has recently been detected in lemon (Citrus limon) orchards in northwest Argentina, causing high levels of damage on fruits. Severe damage results in the rejection of fruit for export, which must then be sold in the industry. However, the restrictions imposed by the citrus industry on insecticide residues sometimes also result in fruit rejection. Here, we studied the ecology and behavior of C. orchidii in order to propose a pest management strategy that could meet both export and industry demands. Seasonal occurrence and canopy distribution of C. orchidii in lemon orchards were evaluated, and field experimental manipulations of thrips populations were performed to analyze how the length (45, 100, 130, and 200 days) and timing (January, February, or March) of C. orchidii activity related with fruit damage. Lemons harvested during summer showed lower infestation levels (∼0.64 individual per fruit) than those harvested in winter (∼1.88 individuals per fruit). Higher proportions of damaged fruits were recorded in the lower part of the tree. Changes in the population levels of C. orchidii were closely associated with fruit phenology. The longer the lemon fruits were exposed to the thrips, the higher was the damage. However, the time of infestations did not affect fruit damage. Our data provide a first step towards understanding the factors that determine the severity of fruit damage caused by C. orchidii in northwest Argentina.

[Giant scrotal lymphedema caused by Milroy's disease]. / Linfedema escrotal gigante por enfermedad de Milroy.

OBJECTIVES: To report a new case of giant scrotal lymphedema due to Milroy's disease, its treatment and outcome. METHODS: A 27-year-old man with generalized congenital lymphedema presented with a giant scrotal mass which interfered with his daily activities and physiological necessities. Physical examination showed a scrotal mass 40 x 40 cm in size and a normal penis. CT scan showed a homogeneous mass, thickened vaginal tunica, and bilateral hydrocele. RESULTS: A surgical procedure was performed including mass resection (5.6 kg), and bilateral hydrocelectomy. Skin defect was covered with skin grafts. CONCLUSIONS: Several therapeutic alternatives have been suggested for Milroy's disease with genital involvement. Nevertheless, when complications are as severe as in the present case, the only valid therapy is surgery.

Linfedema escrotal gigante por enfermedadde Milroy / Giant scrotal lymphedema secondary to Milroy´s disease

OBJETIVO: Presentar un nuevo caso de linfedema escrotal gigante por enfermedad de Milroy, su manejo y evolución. MÉTODOS: Hombre de 27 años, con antecedentes de linfedema congénito, se presenta con masa escrotal gigante que interfiere con su actividad diaria y necesidades fisiológicas. Al examen físico masa escrotal de 40x40 cms aprox., y pene de características normales, TAC con masa homogénea, túnica vaginal engrosada e hidrocele bilateral. RESULTADOS: Se le realiza procedimiento quirúrgico con resección de masa tabicada y fluctuante de 5,6 kgs., se practicó hidrocelectomía bilateral, se cubre el defecto con injerto de piel fina. CONCLUSIÓN: Se han planteado diferentes formas de tratamiento para la enfermedad de milroy con compromiso genital, pero cuando es tan severo la única solución es quirúrgica. (AU)

Health risks caused by freshwater cyanobacteria in recreational waters.

Toxic cyanobacteria are increasingly being perceived as a potential health hazard, particularly in waters used for recreation. A few countries are developing regulations to protect human health from these toxins, and the World Health Organization (WHO) has published both a guideline value for one cyanotoxin in drinking water and a procedural guideline for recreational waters. This article presents an overview of the currently known cyanotoxins and of documented cases of human illnesses attributed to them. It further discusses exposure pathways and approaches to risk management. In this context, the WHO guideline for recreational waters is presented, and monitoring approaches are outlined.

Cáncer glotico : experiencia con 206 casos / Cancer glotico: experience with 206 cases

Se presenta el estudio clínico de 206 pacientes portadores de cáncer glótico atendidos en el Departamento de Cabeza y Cuello del Instituto de Enfermedades Neoplásicas (INEN) durante el periodo comprendido entre 1970, 1990. El cáncer glótico representa en las estadísticas de la institución el 74.9 por ciento de los casos de cáncer de la laringe. El 59.7 por ciento de pacientes con cáncer glotico acudieron a la institución en estadios III y IV, según la clasificación TNM del The American Joint Committe. La política de tratamiento fue administrar radioterapia a los casos considerados tempranos y medianamente avanzados (T1 - T2) y cirugía radical para los casos avanzados (T3 - 4). Las fallas del tratamiento radioterápico fueron tratadas con cirugía de rescate mediante laringectomías parciales, laterales y fronto-laterales o laringectomías totales. Los resultados obtenidos con el tratamiento son similares a los reportados en otros centros, considerando el grado de avance del tumor primario y el estado de los ganglios regionales. El porcentaje global de curación fué de 74.7 por ciento para esta localización de cáncer. La pérdida de la laringe se registro en el 66.5 por ciento de pacientes con cáncer glótico y la incidencia de segundo cáncer primario sincrónico o metacrónico ocurrió en el 7.0 por ciento de los casos.

[Quality of water in the marine environment. The history and application of microbiology standards]. / Calidad del agua en el medio marino. Historia y aplicación de normas microbiológicas.

The history and application of microbiological standards to measure the quality of seawater for primary-contact recreational use and for the harvesting of shellfish are reviewed. Recent research concludes that enterococci, as indicator organisms, provide the most accurate correlation with gastrointestinal disorders attributed to swimming in contaminated waters. Accordingly, a linear relation has been established between mean enterococcus density per 100 ml and swimming associated gastrointestinal disorders per 1,000 population, and in 1984 the U.S. Environmental Protection Agency (EPA) adopted these bacteria as the primary indicator organisms for recreational waters in lieu of the indicators applied up til then, mainly total and fecal coliforms. International, national, and local microbiological standards and guidelines are presented to provide the sanitary engineer with a water quality range for the marine environment. Before adaptation of particular set of standards, local and national circumstances as well as socioeconomic factors should be carefully reviewed. Moreover, the application of quantitative relationships between health risks and the level of indicator organisms should take into account the general health and immunity conditions of the local population.

Efectos extrapancreáticos de las sulfonilureas / Extrapancreatic effects of sulfonylureas

Las sulfonilureas, en particular las de segunda generación, son objeto de un creciente interés debido principalmente a que hoy en día se está comenzando a comprender la fisiopatología de la Diabetes Mellitus no Insulinodependiente (DMNID). La acción hipoglucemiante producida por estos fármacos a corto plazo es conocida desde hace tiempoñ sin embargo su acción a largo plazo no está totalmente clara. Varios son los mecanismos invocados, pero probablemente sólo dos de ellos están involucrados: la potenciación de la acción de la insulina a nivel periférico y la disminución de la producción hepática de glucosa. La potenciación de la acción de la insulina se realiza a nivel posreceptor, teniendo como principal consecuencia una disminución de la insulinorresistencia presente en los pacientes con DMNID. El mecanismo por el cual se produce la disminución de la producción hepatica de glucosa no está tan bien clarificado como el anterior. Sin embargo se ha observado una variación en unn metabolito intracelular, la fructosa 2,6-difosfato, que podría ser uno de los mecanismos subyacentes en los efectos posreceptor de aquellas sulfonilureas

Efectos extrapancreáticos de las sulfonilureas / Extrapancreatic effects of sulfonylureas

Las sulfonilureas, en particular las de segunda generación, son objeto de un creciente interés debido principalmente a que hoy en día se está comenzando a comprender la fisiopatología de la Diabetes Mellitus no Insulinodependiente (DMNID). La acción hipoglucemiante producida por estos fármacos a corto plazo es conocida desde hace tiempoñ sin embargo su acción a largo plazo no está totalmente clara. Varios son los mecanismos invocados, pero probablemente sólo dos de ellos están involucrados: la potenciación de la acción de la insulina a nivel periférico y la disminución de la producción hepática de glucosa. La potenciación de la acción de la insulina se realiza a nivel posreceptor, teniendo como principal consecuencia una disminución de la insulinorresistencia presente en los pacientes con DMNID. El mecanismo por el cual se produce la disminución de la producción hepatica de glucosa no está tan bien clarificado como el anterior. Sin embargo se ha observado una variación en unn metabolito intracelular, la fructosa 2,6-difosfato, que podría ser uno de los mecanismos subyacentes en los efectos posreceptor de aquellas sulfonilureas (AU)

Bioterapia de la diarrea del niño desnutrido / Biotheraphy of diarrhea in undernourished children

El ecosistema microbiano enteral, capaz de resistir o autocorrregir alteraciones de su composición, resulta totalmente pervertido en casos de desnutrición, lo que explica el complejo cuadro de la Enteropatía Ambiental. Esta situación es modificable por la ingesta de lactobacilos seleccionados por su actividad antimicrobiana, enzimática e inmunopotenciadora. 137 niños hospitalizados por este cuadro recibieron como único tratamiento leche fermentada por lactobacilos, contrastando el resultado con el obtenido en 33 niños tratados con leche libre de lactosa y antibióticos no absorbibles. Los grupo estaban conformados por un 26% de desnutridos de 1§; 41% de 2§ y 33% de 3§. Todos marasmáticos. El resultado se midió en días desde el inicio del tratamiento hasta la eliminación de heces pastosas y fue de 3,5 días promedio para el grupo tratado con leche fermentada y 7 días para el grupo control. La efectividad del tratamiento alcanzó el 0.97. Estos resultados impulsan la idea de estar en presencia de un alimento-medicamento de gran potencialidad, bajo costo y fácil preparación domiciliaria por lo que resultaría de gran utilidad en la primera barrera sanitaria. Pero se destaca que un orden social más ético que permita el equilibrio biológico adecuado de la especie humana sería la mejor solución para este tipo de problemas de salud

Bioterapia de la diarrea del niño desnutrido / Biotheraphy of diarrhea in undernourished children

El ecosistema microbiano enteral, capaz de resistir o autocorrregir alteraciones de su composición, resulta totalmente pervertido en casos de desnutrición, lo que explica el complejo cuadro de la Enteropatía Ambiental. Esta situación es modificable por la ingesta de lactobacilos seleccionados por su actividad antimicrobiana, enzimática e inmunopotenciadora. 137 niños hospitalizados por este cuadro recibieron como único tratamiento leche fermentada por lactobacilos, contrastando el resultado con el obtenido en 33 niños tratados con leche libre de lactosa y antibióticos no absorbibles. Los grupo estaban conformados por un 26% de desnutridos de 1º; 41% de 2º y 33% de 3º. Todos marasmáticos. El resultado se midió en días desde el inicio del tratamiento hasta la eliminación de heces pastosas y fue de 3,5 días promedio para el grupo tratado con leche fermentada y 7 días para el grupo control. La efectividad del tratamiento alcanzó el 0.97. Estos resultados impulsan la idea de estar en presencia de un alimento-medicamento de gran potencialidad, bajo costo y fácil preparación domiciliaria por lo que resultaría de gran utilidad en la primera barrera sanitaria. Pero se destaca que un orden social más ético que permita el equilibrio biológico adecuado de la especie humana sería la mejor solución para este tipo de problemas de salud (AU)

[Carcinoembryonic antigen in ascites and pleural effusions]. / Antigène carcino-embryonnaire dans les ascites et les épanchements pleuraux.

The purpose of this prospective study was to evaluate the usefulness of carcinoembryonic antigen (CEA) assays in effusion fluids for the diagnosis of cancer. From 1978 to 1981, 63 patients totaling 67 effusions were investigated for malignant cells and CEA concentrations. There were 62 cases of ascites and 5 cases of pleural effusion resulting from 35 cirrhoses and 28 cancers, including 17 adenocarcinomas. Macroscopic examination of serous membranes was possible in 24 patients. CEA concentrations at least 4 times higher than the upper limit of normal laboratory values were required to diagnose malignancy in effusions. The specificity of both cytology and CEA assays was 100 p. 100 in cirrhotic ascites. Malignant cells were present in 14 cases and positive CEA levels in 19 cases. CEA concentrations were highly significant (p less than 0.001) of cancerous effusions due to adenocarcinomas. In cancers other than adenocarcinoma and in hepatocarcinoma, CEA assays did not prove useful, and cytological examination remained the best diagnostic method. Both cytology and CEA levels were positive for malignancy in 11 effusions, and a diagnosis of cancer could be made on these grounds in 22 out 28 cases. Lack of correlation between CEA concentrations in sera and in effusion fluids suggests local production consecutive to invasion of the serous membranes. All 8 adenocarcinoma patients with grossly detectable extension to the peritoneum had high CEA concentrations, but malignant cells were absent in 4 cases. This discrepancy might tentatively be explained by local dissemination via the lymphatic system without disruption of the membrane but resulting in reflux of CEA into the effusion fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

Developing alternative approaches to urban wastewater disposal in Latin America and the Caribbean

The explosive rate of urbanization and industrialization in Latin America and the Caribbean has aggravated serious wastewater disposal problems. To address those problems, sound pollution control programs are needed - programs that are founded on a firm legal base and supported by an institutional infrastructure suitable for their effective operation. Such programs should make a point of employing technologies that are appropriate for the climatic and economic conditions prevailing in the areas they serve. Promising methods for dealing with such problems include use of submarine outfalls with minimal pretreatment for cities along coasts and estuaries, maximum use of receiving waters' assimilative capacity (as determined through application of system management and water quality models), reuse of treated sewage effluent for irrigation, and the application of unconventional technology for urban slum sanitation. This article reviews those various approches and describes the ongoing collaboration between national governments and PAHO's Pan American Center for Sanitary Engineering and Environmental Sciences (CEPIS) in the areas of research, information exchange, human resources development, and institutional development for the purpose of establishing a viable strategy and framework through which these major problems can be confronted and perhaps ultimately over come.(AU)

[Associated granular cell tumor and esophageal cancer (author's transl)]. / Association d'une tumeur à cellules granuleuses et d'un cancer de l'oesophage.

The first reported case of an association of Abrikossof's tumor and a cancer in the esophagus is described. After a general view of the published literature on these tumors, their clinical and pathological characteristics are outlined, and their histogenesis envisaged in relation to histochemical and ultrastructural findings. Therapeutic methods and means of follow-up surveillance are defined.