Dirofilaria immitis en caninos del medio Sinú: un posible riesgo para la salud pública / Dirofilaria immitis in canines of middle Sinú: a potential risk for public health

Resumen Introducción: Dirofilaria immitis es un parásito de distribución mundial, en caninos produce la dirofilariosis cardiopulmonar progresiva, afección localizada en las arterias pulmonares y el ventrículo derecho, que induce a daño endotelial y neumonitis. El parásito es trasmitido por la picadura de mosquitos a caninos y a otras especies, inclusive a humanos que habitan zonas endémicas, constituyéndose en una zoonosis. En Colombia D. immitis ha sido reportada en diferentes regiones de Colombia. Objetivo: Determinar anticuerpos contra D. immitis en caninos de Cereté, Ciénaga de Oro y San Carlos, municipios del Medio Sinú (Córdoba). Materiales y métodos: Mediante un estudio descriptivo de corte trasversal y un muestreo estratificado, se tomaron 105 muestras de sangre en caninos de las áreas urbanas de estos municipios; la determinación de antígenos de D. immitis, se realizó mediante un inmunoensayo enzimático. Se usó estadística descriptiva y se empleó Chi-cuadrado para determinar si hubo diferencias significativas con respecto a la seropositividad y las variables evaluadas (edad, raza y procedencia). Resultados: La seroprevalencia fue del 5.7% y los anticuerpos se detectaron en todos los municipios evaluados. No se encontraron diferencias estadísticas entre seropositividad por municipio, edad, raza, sexo. Conclusiones: El hábitat de los humanos en los municipios del medio Sinú, junto con la detección de anticuerpos circulantes en caninos de D. immitis, las condiciones agroecológicas de esta región, la presencia de mosquitos y hospederos, puede hacer que los humanos sean expuestos a la transmisión de patógenos y ser un riesgo para la salud pública; por lo cual se hace necesario implementar medidas de prevención y control de vectores.

Abstract Introduction: Dirofilaria immitis, is a worldwide distribution parasite that causes progressive cardiopulmonary disease in dogs, it is located in the pulmonary arteries and right ventricle and produces endothelial injury and pneumonia. It is transmitted by mosquito bites to canines, but it may be found in a variety of mammals, including humans living in endemic areas, which turns it into a zoonosis. The infection has been reported in different Colombian regions. Objective: To determine antibodies against D. immitis in dogs of Cereté, Ciénaga de Oro, and San Carlos, municipalities of middle Sinú (Córdoba). Materials and methods: Blood samples of 105 crossbreed dogs were collected from the urban areas of these municipalities in order to conduct a descriptive cross-sectional study and stratified sampling. Antibody to Dirofilaria immitis was measured through the implementation of an enzyme-linked immunosorbent assay (ELISA). Descriptive analysis and Chi-square were used to determine whether there were significant differences with respect to D. immitis seropositivity and the parameters investigated (age, race and geographic region of origin). Results: The seroprevalence to D. immitis was 5.7%, and the antibodies were detected in the municipalities evaluated. No statistically significant differences were observed between the seropositivity of different age groups, races, sexes, and municipalities. Conclusions: The presence of circulating antibodies of Vectors and hosts involved in the transmission may represent a potential public health risk in which humans can act as aberrant hosts.

California's COVID-19 Virtual Training Academy: Rapid Scale-Up of a Statewide Contact Tracing and Case Investigation Workforce Training Program.

Case investigation (CI) and contact tracing (CT) are key to containing the COVID-19 pandemic. Widespread community transmission necessitates a large, diverse workforce with specialized knowledge and skills. The University of California, San Francisco and Los Angeles partnered with the California Department of Public Health to rapidly mobilize and train a CI/CT workforce. In April through August 2020, a team of public health practitioners and health educators constructed a training program to enable learners from diverse backgrounds to quickly acquire the competencies necessary to function effectively as CIs and CTs. Between April 27 and May 5, the team undertook a curriculum design sprint by performing a needs assessment, determining relevant goals and objectives, and developing content. The initial four-day curriculum consisted of 13 hours of synchronous live web meetings and 7 hours of asynchronous, self-directed study. Educational content emphasized the principles of COVID-19 exposure, infectious period, isolation and quarantine guidelines and the importance of prevention and control interventions. A priority was equipping learners with skills in rapport building and health coaching through facilitated web-based small group skill development sessions. The training was piloted among 31 learners and subsequently expanded to an average weekly audience of 520 persons statewide starting May 7, reaching 7,499 unique enrollees by August 31. Capacity to scale and sustain the training program was afforded by the UCLA Extension Canvas learning management system. Repeated iteration of content and format was undertaken based on feedback from learners, facilitators, and public health and community-based partners. It is feasible to rapidly train and deploy a large workforce to perform CI and CT. Interactive skills-based training with opportunity for practice and feedback are essential to develop independent, high-performing CIs and CTs. Rigorous evaluation will continue to monitor quality measures to improve the training experience and outcomes.

Successful use of N-acetylcysteine to treat severe hepatic injury caused by a dietary fitness supplement.

In the absence of adequate premarketing efficacy and safety evaluations, adverse events from over-the-counter supplements are emerging as a public health concern. Specifically, bodybuilding products are being identified as a frequent cause of drug-induced liver injury. We present a case of a 20-year-old Hispanic male who presented with acute nausea and vomiting accompanied by severe right upper quadrant abdominal pain, shivering, and shortness of breath. Laboratory data pointed to mixed cholestatic and hepatocellular damage, and after exclusion of known alternate etiologies, the patient was diagnosed with acute drug-induced liver injury secondary to the use of "Friction," a bodybuilding supplement. Treatment with N-acetylcysteine (NAC) 20% oral solution was initiated empirically at a dose of 4000 mg [DOSAGE ERROR CORRECTED] (70 mg/kg) every 4 hours and was continued once the diagnosis was made. Within 48 hours of admission to our hospital, the patient began to show clinical resolution of right abdominal pain and tolerance to oral diet associated with a significant decline toward normal in his liver function tests and coagulopathy. The WHO-UMC causality assessment system suggested a "certain causality" between exposure to the supplement and the acute liver injury. In the event of suspected drug-induced liver injury, treatment with NAC should be considered given its favorable risk-benefit profile.

Urbanization, land tenure security and vector-borne Chagas disease.

Modern cities represent one of the fastest growing ecosystems on the planet. Urbanization occurs in stages; each stage characterized by a distinct habitat that may be more or less susceptible to the establishment of disease vector populations and the transmission of vector-borne pathogens. We performed longitudinal entomological and epidemiological surveys in households along a 1900 × 125 m transect of Arequipa, Peru, a major city of nearly one million inhabitants, in which the transmission of Trypanosoma cruzi, the aetiological agent of Chagas disease, by the insect vector Triatoma infestans, is an ongoing problem. The transect spans a cline of urban development from established communities to land invasions. We find that the vector is tracking the development of the city, and the parasite, in turn, is tracking the dispersal of the vector. New urbanizations are free of vector infestation for decades. T. cruzi transmission is very recent and concentrated in more established communities. The increase in land tenure security during the course of urbanization, if not accompanied by reasonable and enforceable zoning codes, initiates an influx of construction materials, people and animals that creates fertile conditions for epidemics of some vector-borne diseases.

Histeroscopia de consultorio: evaluación del dolor / Office hysteroscopy: pain assessment

Objetivo: Evaluar el dolor durante la histeroscopia de consultorio, sin anestesia e investigar los factores relacionados. Métodos: Estudio prospectivo, descriptivo, analítico y de corte transversal en una población de 309 pacientes de la Maternidad “Concepción Palacios” que acudieron al Servicio de Ginecología entre agosto 2010 y agosto 2011, quienes tenían indicación para histeroscopia. Se registraron antecedentes y datos clínicos relacionados con la percepción del dolor, así como la intensidad de dolor percibida mediante una escala análoga de 0 al 10. Resultados: Se obtuvo una media de percepción de dolor de 2,9. La percepción de dolor fue leve en 56.%, dolor moderado: 36,2 %, dolor intenso: 4,9 %, dolor intolerable: 2,9 %, nada de dolor: 4,2 %. No se encontró relación entre la percepción de dolor y la edad, paridad, estado hormonal, indicación del estudio ni tipo de procedimiento. El 60,6 % de las pacientes con cuello permeable, presentaron dolor leve, mientras que las que tenían sinequias o estenosis lo presentaron en 25,5 % y 31, 3 % respectivamente. Con cuello permeable hubo 0,4 % de dolor intolerable y en presencia de sinequias la cifra fue 12,5 % (P<0,05). 88,8.% de las pacientes con dolor intolerable presentaban estenosis o sinequias. Conclusiones: La histeroscopia de consultorio es un procedimiento bien tolerado por la mayoría de las pacientes; es independiente de la paridad, condición hormonal, indicación del estudio, edad y tipo de procedimiento. La percepción de dolor fue mayor en pacientes con estenosis o sinequias cervicales.

Objective: Assess pain during no anesthesia office hysteroscopy and investigate related factors. Method: Prospective, descriptive, analytical and cross-section study in a population of 309 patients who attended the gynaecology service of Maternidad Concepción Palacios between August 2010 and August 2011, who had indication for hysteroscopy. Background and clinical data was collected, relating to the perception of pain, as well as the intensity of pain perceived by means of an analog scale of 0 to 10. Results: An average of 2.9 pain perception. The perception of pain was mild in 56 %, moderate pain: 36.2 %, severe pain: 4.9 %, intolerable pain: 2.9 %, none of pain: 4.2 per cent. No relationship was found between the perception of pain and age, parity, hormonal state, indication of the study or type of procedure. 60.6 % of patients with permeable cervix presented mild pain, while if they had adhesions or stenosis the mild pain was present in 25.5 % and 31, 3 % respectively. With permeable cervix there was 0.4 % of intolerable pain and in the presence of adhesions was only 12.5 % (P < 0,05), 88.8 % of patients with intolerable pain had cervical stenosis or adhesions. Conclusions: Office hysteroscopy is a procedure well tolerated by most patients; It is independent of parity, hormonal condition, indication of the study, age and type of procedure. The perception of pain was greater in patients with cervical stenosis or adhesions.

[Reaction of Leishmania (Leishmania) mexicana antigens by sera of patients with cutaneous leishmaniasis from Sinaloa, Mexico]. / Reacción de antígenos de Leishmania (Leishmania) mexicana con sueros de pacientes con leishmaniosis cutánea de Sinaloa, México.

OBJECTIVE: To detect Leishmania mexicana antigens reacting with sera of patients with cutaneous leishmaniasis (CL). MATERIAL AND METHODS: A crude extract of L. mexicana was used as antigen for 2-D Western blot using sera from 5 patients with CL and controls from Sinaloa, Mexico during 2008. RESULTS: Five antigens were detected in the five infected patients analyzed; their molecular weights and isoelectric points were: 26 kDa (pI 7.8), 27 kDa (pI 8.1), 28 kDa (pI 8.6), 29 kDa (pI 8.5) and 31 kDa (pI 9.0). CONCLUSION: New potentially immunodominant L. mexicana antigens were detected, suggesting that this parasite could be the species responsible for human infection in Sinaloa.

Reacción de antígenos de Leishmania (Leishmania) mexicana con sueros de pacientes con leishmaniosis cutánea de Sinaloa, México / Reaction of Leishmania (Leishmania) mexicana antigens by sera of patients with cutaneous leishmaniasis from Sinaloa, Mexico

OBJETIVO: Detectar los antígenos de Leishmania (Leishmania) mexicana que reaccionan con sueros de pacientes con leishmaniosis cutánea (LC) de Sinaloa, México. MATERIAL Y MÉTODOS: Un extracto crudo de L. (L.) mexicana fue usado como antígeno para Western blots 2-D empleando sueros de cinco pacientes con LC y controles originarios de Sinaloa, México, durante el 2008. RESULTADOS: Cinco antígenos fueron detectados sólo por los sueros de los cinco pacientes estudiados; estos son: 26 kDa (pI 7.8), 27 kDa (pI 8.1), 28 kDa (pI 8.6), 29 kDa (pI 8.5) y 31 kDa (pI 9.0). CONCLUSIONES: Se detectaron nuevos antígenos de L. (L.) mexicana potencialmente inmunodominantes, lo que sugiere a este parásito como el agente causal de la LC en Sinaloa.

OBJECTIVE: To detect Leishmania mexicana antigens reacting with sera of patients with cutaneous leishmaniasis (CL). MATERIAL AND METHODS: A crude extract of L. mexicana was used as antigen for 2-D Western blot using sera from 5 patients with CL and controls from Sinaloa, Mexico during 2008. RESULTS: Five antigens were detected in the five infected patients analyzed; their molecular weights and isoelectric points were: 26 kDa (pI 7.8), 27 kDa (pI 8.1), 28 kDa (pI 8.6), 29 kDa (pI 8.5) and 31 kDa (pI 9.0). CONCLUSION: New potentially immunodominant L. mexicana antigens were detected, suggesting that this parasite could be the species responsible for human infection in Sinaloa.

The GABA-B antagonist 2-hydroxysaclofen reverses the effects of baclofen on the discriminative stimulus effects of D-amphetamine in the conditioned taste aversion procedure.

Some of the behavioral effects of d-amphetamine (d-AMPH) are mediated by an increase in dopamine neurotransmission in the nucleus accumbens. However, there is evidence that gamma-amino-butyric-acid-B (GABA-B) receptors are involved in some behavioral effects of D-AMPH and cocaine. Here, we examined the effects of baclofen on the discriminative stimulus properties of D-AMPH, using conditioned taste aversion (CTA) as the drug discrimination procedure. Male Wistar rats were deprived of water and trained in the CTA procedure. They received D-AMPH (1 mg/kg, i.p.) before gaining access to saccharin, which was followed by an injection of LiCl. On alternate days, the subjects received saline before and after the access to saccharin. After the rats learned the D-AMPH-saline discrimination, the standard dose of D-AMPH was replaced by different doses of D-AMPH, baclofen (a GABA-B receptor agonist), 2-hydroxysaclofen (a GABA-B receptor antagonist), a combination of baclofen+D-AMPH, or a combination of 2-hydroxysaclofen+baclofen+D-AMPH. Baclofen did not substitute for D-AMPH, but, when combined with D-AMPH, it produced a small but significant decrease in the discriminative stimulus effects of D-AMPH. This effect was reversed by administration of 2-hydroxysaclofen. These data suggest that GABA-B receptors play a regulatory role in the discriminative stimulus effects of D-AMPH.

RNA silencing-mediated resistance to a crinivirus (Closteroviridae) in cultivated sweet potato (Ipomoea batatas L.) and development of sweet potato virus disease following co-infection with a potyvirus.

Sweet potato chlorotic stunt virus (SPCSV; genus Crinivirus, family Closteroviridae) is one of the most important pathogens of sweet potato (Ipomoea batatas L.). It can reduce yields by 50% by itself and cause various synergistic disease complexes when co-infecting with other viruses, including sweet potato feathery mottle virus (SPFMV; genus Potyvirus, family Potyviridae). Because no sources of true resistance to SPCSV are available in sweet potato germplasm, a pathogen-derived transgenic resistance strategy was tested as an alternative solution in this study. A Peruvian sweet potato landrace 'Huachano' was transformed with an intron-spliced hairpin construct targeting the replicase encoding sequences of SPCSV and SPFMV using an improved genetic transformation procedure with reproducible efficiency. Twenty-eight independent transgenic events were obtained in three transformation experiments using a highly virulent Agrobacterium tumefaciens strain and regeneration through embryogenesis. Molecular analysis indicated that all regenerants were transgenic, with 1-7 transgene loci. Accumulation of transgene-specific siRNA was detected in most of them. None of the transgenic events was immune to SPCSV, but ten of the 20 tested transgenic events exhibited mild or no symptoms following infection, and accumulation of SPCSV was significantly reduced. There are few previous reports of RNA silencing-mediated transgenic resistance to viruses of Closteroviridae in cultivated plants. However, the high levels of resistance to accumulation of SPCSV could not prevent development of synergistic sweet potato virus disease in those transgenic plants also infected with SPFMV.

Modulatory role of 5-HT1B receptors in the discriminative signal of amphetamine in the conditioned taste aversion paradigm.

Drugs of abuse, such as amphetamine (AMPH), share the ability to activate the mesolimbic dopamine (DA) system. The behavioral effects of AMPH are largely mediated by increased DA neurotransmission in the nucleus accumbens. However, there is evidence that serotonin (5-hydroxytryptamine - 5-HT) systems may regulate forebrain DA function. We examined the role of 5-HT1B receptors on the discriminative stimulus properties of AMPH using conditioned taste aversion (CTA) as the drug discrimination procedure. Male Wistar rats were deprived of water and trained in the CTA procedure. They received the administration of AMPH (1.0 mg/kg) before a 10 min period of access to saccharin solution and followed by an injection of LiCl; on alternate days, rats received saline before and after the access to saccharin solution. In generalization and combination tests, the training dose of AMPH was substituted by 5-HT1B receptor ligands RU24969 (5-HT1B agonist: 0.1, 0.3 and 1.0 mg/kg), CP94253 (5-HT1B agonist: 1.0, 3.0 and 5.6 mg/kg) and GR127935 (5-HT1B antagonist: 0.3, 1.0 and 3.0 mg/kg) or a combination of RU24969 (0.1, 0.3 and 1.0 mg/kg), CP94253 (1.0, 3.0 and 5.6 mg/kg) or GR127935 (0.3, 1.0 and 3.0 mg/kg) with AMPH (0.3 mg/kg) or GR127935 (0.3, 1.0 and 3.0 mg/kg) and CP94253 (5.6 mg/kg) with AMPH (0.3 mg/kg). The results showed that 5-HT1B agonists RU24969 and CP94253 produced partial generalization of 48% and 60%, respectively, and the 5-HT1B antagonist GR127935 neither substituted for AMPH nor affected the discriminative cue of AMPH; however, when RU24969 or CP94253 were administrated in combination with AMPH, they increased the discriminative cue of AMPH. This effect was reversed by the administration of 5-HT1B antagonist GR127935. These data suggest that 5-HT1B receptors play a modulatory role in the discriminative cue of AMPH.

Diagnostic accuracy of bronchoalveolar lavage samples in immunosuppressed patients with suspected pneumonia: analysis of a protocol.

BACKGROUND: Fast and accurate etiologic diagnosis of pneumonia in immunocompromised patients is essential for a good outcome. Utility of bronchoalveolar lavage (BAL) samples has already been established, but studies about them are scarce and limited to few countries. We aimed to evaluate the accuracy of a diagnostic protocol, emphasizing on local epidemiology, rapidity, and yield of different techniques. METHODS: One year prospective study of 101 consecutive immunosuppressed patients admitted with suspected pneumonia to a university hospital. They all had bronchoscopic BAL (n=109) and respiratory sampling. Conventional microbiological studies, cytomegalovirus pp65 antigenemia and transbronchial biopsy (TBB), whenever considered pertinent, were done. Results were analyzed along with other diagnostic procedures, clinical course and final outcome. RESULTS: HIV/AIDS infection was the most frequent cause of inclusion (n=80). Infections accounted for 79 out of 122 final diagnoses (64.8%). Our protocol identified 60 infectious and 3 noninfectious pathologies (general yield: 51.6%). Sensitivity in pulmonary infections was 75.9% (IC95%: 64.8-84.6%), specificity 86.0% (72.6-93.7%), positive predictive value 89.6% (79.1-95.3%), negative predictive value 69.4% (56.2-80.1%), accuracy 79.8% (71.7-86.2%). Mycobacterium spp. (n=27), bacteria (n=19), Pneumocystis jirovecii (n=18) and other fungi (histoplasmosis: 6, aspergillosis: 5, cryptococosis: 3) were the most common infectious pathogens. Direct microscopy allowed an early definite/presumptive diagnosis in 36/49 fungal and mycobacterial infections (73.5%). Up to 30% of mycobacterial infections were missed. CONCLUSIONS: Systematical study of BAL samples has a high diagnostic yield in our immunocompromised patients with suspected pneumonia. As economical and epidemiological conditions of regions are different, it should be tried everywhere.

A novel thioredoxin h is secreted in Nicotiana alata and reduces S-RNase in vitro.

Thioredoxins type h are classified into three subgroups. The subgroup II includes thioredoxins containing an N-terminal extension, the role of which is still unclear. Although thioredoxin secretion has been observed in animal cells, there is no evidence suggesting that any thioredoxin h is secreted in plants. In this study, we report that a thioredoxin h, subgroup II, from Nicotiana alata (NaTrxh) is secreted into the extracellular matrix of the stylar transmitting tract tissue. Fractionation studies showed that NaTrxh is extracted along with well characterized secretion proteins such as S-RNases and NaTTS (N. alata transmitting tissue-specific protein). Moreover, an NaTrxh-green fluorescent fusion protein transiently expressed in Nicotiana benthamiana and Arabidopsis thaliana leaves was also secreted, showing that NaTrxh has the required information for its secretion. We performed reduction assays in vitro to identify potential extracellular targets of NaTrxh. We found that S-RNase is one of the several potential substrates of the NaTrxh in the extracellular matrix. In addition, we proved by affinity chromatography that NaTrxh specifically interacts with S-RNase. Our findings showed that NaTrxh is a new thioredoxin h in Nicotiana that is secreted as well as in animal systems. Because NaTrxh is localized in the extracellular matrix of the stylar transmitting tract and its specific interaction with S-RNase to reduce it in vitro, we suggest that this thioredoxin h may be involved either in general pollen-pistil interaction processes or particularly in S-RNase-based self-incompatibility.

Correlación entre los cambios hemodinámicos de la aorta abdominal intrauterina / Correlation between the hemodynamic changes of the fetal abdominal aorta and the retard of intrauterine growth

El objetivo de este trabajo es valorar por Doppler Duplex Color el comportamiento de la aorta abdominal fetal en la fisiopatología del retardo de crecimiento intra uterino (R.C.I.U), dado que en la bibliografía mundial existen discordancias respecto de este tópico.Este es un estudio prospectivo y comparativo, en el cual se evaluó a mujeres embarazadas entre 25 y 38 semanas de gestación distribuidas en dos grupos. Grupo A: 27 pacientes con R.C.I.U. diagnosticado por clínica, ecografía y confirmación posnatal; grupo B: 30 pacientes con embarazos normales valoradas por iguales parámetros (grupo control). Se establecieron los valores Indice de Resistencia de Pourcelot de aorta abdominal fetal en ambos grupos. Solamente una paciente del grupo A mostró cambios hemodinámicos en la aorta abdominal fetal (aumento del IR). Las restantes 26 pacientes de este grupo presentaron valores concordantes con los del grupo control. Conclusión: el Doppler Color de aorta abdominal fetal no es útil como predictor de R.C.I.U

Macroproyecto de investigación: factores de riesgo de la violencia en Colombia / Research macro project: risk factors for violence in Colombia

El presente proyecto de investigación ha tenido en cuenta con especial atención los aspectos relacionados con la gerencia del proyecto. A continuación se presenta una breve síntesis de las motivaciones al respecto y en el Capítulo V se amplía toda la información sobre el tema, a nivel de planeación, organización y control del proyecto en consideración. Los problemas gerenciales con los proyectos de investigación han sido manifiestos. Muy comúnmente tales realizaciones presentan con las variables de tiempo y de costo, además de las relacionadas con los objetivos logrados y métodos de investigación como tal. Ello ha imposibilitado en muchos casos la consecución de apoyo y soporte financiero por parte de entidades nacionales y extranjeras. La razón de tal estado de cosas parece radicar tanto en la ausencia de modelos gerenciales que puedan aplicarse a los trabajos de investigación como a ala propia actitud de los investigadores frente al tema de la gestión de la realización. Consiente de lo anterior, este proyecto de investigación asigna una importancia capital al tema de la gerencia del proyecto, asume la investigación con un enfoque gerencial y utiliza desde la propia formulación y planeación del proyecto elementos de reciente desarrollo para los proyectos de este tipo, como los que se pueden apreciarse en el capitulo V, ya referido. Como logros actuales del enfoque gerencial propuesto pueden mencionarse los siguientes: el proyecto es enfrentado de una manera integral, es un macroproyecto, tanto desde el punto de vista de la temática como de sus relaciones con el entorno. En efecto, la temática será asumida desde la teoría con un modelo holístico centrado básicamente en tres aspectos mutuamente relacionados. Individuo, familia y educación

Conducta antisocial: contexto teórico, factores de desarrollo y formulación / Antisocial behaviour: theoretical context, development factors and formulación

Esta monografía tiene por objeto desarrollar un marco teórico basado en los datos existentes de investigación sobre los factores que determinan en el desarrollo de la conducta antisocial y que constituya un marco de referencia para el desarrollo de proyectos de investigación y programas de prevención de conducta antisocial desde las diversas perspectivas desde las que se han enfocado, Puesto que se han dado diversas definiciones de la agresión desde distintos puntos de vista, lo cual muchas veces crea confusiones en los estudios de investigación , en la primera sección nos ocuparemos de discutir y precisar los problemas de definición que permitan unificar criterios sobre el objeto de estudio. A partir de tales criterios, en la segunda sección se considerarán los elementos de taxonomía y clasificación de la conducta agresiva desde una perspectiva de la psicología clínica. Se revisarán los estudios en los que se relaciona la conducta antisocial con otros desordenes de conducta, esto es, la investigación sobre morbilidad de la conducta agresiva. Como estos trabajos sobre taxonomía y clasificación arrojan luz sobre la relación entre conducta agresiva y otras dimensiones del comportamiento, se introduce el tema de la tercera sección, que estará dedicada a examinar detalladamente las características distintivas de la conducta agresiva, derivadas principalmente de los trabajos de investigación desde una perspectiva longitudinal de desarrollo. En la curta sección, se describirán las principales líneas de investigación sobre el desarrollo de la conducta agresiva haciendo énfasis especialmente en los estudios sobre vías de desarrollo. En la quinta sección, se hará un análisis sobre los datos disponibles en la investigación de los múltiples procesos a nivel individual, familiar y social que intervienen en la adquisición y mantenimiento antisocial.