Carlos Giraldo

Homicides in Medellín, Colombia, from 1990 to 2002: victims, motives and circumstances

In Medellín, Colombia, homicide has been the first cause of morbidity and mortality for 20 years. Medellín has the highest homicide rates of all major cities in Latin America. This study describes the victims, motives, and circumstances in homicides in Medellín from 1990 to 2002. The period included 55,365 homicides, of which 1,394 were randomly studied. Of this sample, 93.6% (95%CI: 92.2%-94.8%) were males, 77.0% (95%CI: 75.0%-79.5%) less than 35 years of age, one-fourth had consumed alcohol, and nine out of ten were killed with firearms. The main motives were revenge and armed robbery. 37.0% (95%CI: 34.0%-41.0%) of the victims lived in the lowest socioeconomic stratum of the city. Characteristics of homicides in Medellín have remained unchanged since the 1980s, when the most violent period in the citys history began. The most heavily affected groups are young males who live and die in poor neighborhoods, and the murders are individual acts that leave no wounded behind.

Classifying psychotic disorders: issues regarding categorial vs. dimensional approaches and time frame to assess symptoms

The studys aims were to empirically derive classes of disorders and dimensional syndromes within psychotic disorders on the basis of the three time frames of symptom assessment and to comparatively examine their external validity. The level of concordance among classes and among dimensions across the time frames was generally low. The external correlates of psychopathological syndromes differed as a function of both type of assessment and the dimensional or categorical approach used. The dimensional approach was more effective than the categorical approach in predicting a set of clinical variables, irrespective of the time frame used to assess the symptoms. It is concluded that classification of psychotic disorders is highly dependent upon the time frame considered to assess symptoms and that dimensional classifications do have higher predictive power than categorical ones.

Treinta años de homicidios en Medellín, Colombia, 1979-2008

El homicidio en Medellin, Colombia, se convirtio en la primera causa de muerte desde 1986 y su participacion del total de muertes paso de 3,5% en 1976 a 42% en 1991 y 7% en 2006. Entre 1979 y 2008 hubo 81.166 homicidios (2.706 promedio/ano). La tasa de homicidios por 100.000 habitantes fue 44 en 1979 y 47 en 2008, con un maximo de 388 en 1991. Se describen caracteristicas de los homicidios en 30 anos, entre 1979 y 2008, por quinquenios, mediante una muestra aleatoria de 3.414 necropsias medico-legales. Los muertos fueron hombres 92.8% (IC95%: 91,8; 93,6), jovenes con promedios de edad entre 27 y 33 anos, residentes en estratos socio-economicos bajos, con predomino de los moviles ajustes de cuentas, rinas y atracos. Se evidenciaron tres periodos diferentes de la epidemia de homicidios: el primero de incremento acelerado 15 anos, el segundo de descenso sostenido hasta 1998 y el tercero ondulante y descenso abrupto en los 10 ultimos anos. Estos resultados de larga duracion de la violencia en la ciudad abren posibilidades analiticas para encontrar politicas mas consistentes de intervencion.

Plasma and Brain Cholinesterase in Methomyl-Intoxicated Free-Ranging Pigeons (Columba Livia f. Domestica)

A mortality event caused by exposure to the carbamate insecticide methomyl was diagnosed in several hundred pigeons fed treated corn kernels in a city park. A cholinesterase inhibitor insecticide was initially suspected based on clinical signs and a significant inhibition (P < 0.05) of brain cholinesterase (ChE) activity compared with normal values for the species. However, brain ChE activity was within the normal range in birds subsequently submitted in an advanced stage of autolysis. Two groups of 10 healthy pigeons were allocated into a control group and an experimental group, which was offered corn samples retrieved from the incident site. Within minutes of ingesting the contaminated corn, the birds became immobile, had transient wing fluttering, and developed profuse salivation immediately followed by death. Plasma ChE activity at death had declined by more than 95% of preexposure levels (0.04 ± 0.02 vs. 1.56 ± 0.23 μmol/min per milliliter). Brain activity in the sagittal brain sections that were immediately frozen after death was inhibited by ≥50% of control birds (13.5 ± 2.2 vs. 27.5 ± 1.8 μmol/min per gram). However, the sagittal sections left for 1.5 days at ambient temperature of 25°C had normal or higher activity, an effect that was attributed to a combination of spontaneous reactivation and dehydration. After incubation of both plasma and brain homogenates for 1 hr at 37°C, ChE activity recovered by 2- and 1.46-fold, respectively. An organophosphorus and carbamate screen conducted by 2 independent laboratories identified and quantified methomyl in treated kernels at 400 ppm. These results indicate that spontaneous reactivation and dehydration can mask previous reductions in ChE activity.