Characterization of inflammatory bowel disease in Colombia: Results of a national register. / Caracterización de la enfermedad inflamatoria intestinal en Colombia: resultados de un registro nacional.

AIM: To determine the clinical, sociodemographic, and treatment characteristics of inflammatory bowel disease (IBD) in a Colombian population register. METHODS: A descriptive, analytic, observational, cross-sectional, multicenter study on patients with IBD from 17 hospital centers in 9 Colombian cities was conducted. RESULTS: A total of 2,291 patients with IBD were documented, 1,813 (79.1%) of whom presented with ulcerative colitis (UC), 456 (19.9%) with Crohn's disease (CD), and 22 with IBD unclassified (0.9%). The UC/CD ratio was 3.9:1. A total of 18.5% of the patients with UC and 47.3% with CD received biologic therapy. Patients with extensive UC had greater biologic therapy use (OR = 2.78, 95% CI: 2.10-3.65, p = 0.000), a higher surgery rate (OR = 5.4, 95% CI: 3.5-8.3, p = 0.000), and greater frequency of hospitalization (OR = 4.34, 95% CI: 3.47-5.44, p = 0.000). Patients with severe UC had greater biologic therapy use (OR = 5.04, 95% CI: 3.75-6.78, p = 0.000), a higher surgery rate (OR = 8.64, 95% CI: 5.4-13.78, p = 0.000), and greater frequency of hospitalization (OR = 28.45, 95% CI: 19.9-40.7, p = 0.000). CD patients with inflammatory disease behavior (B1) presented with a lower frequency of hospitalization (OR = 0.12, 95% CI: 0.07-0.19, p = 0.000), a lower surgery rate (OR = 0.08, 95% CI: 0.043-0.15, p = 0.000), and less biologic therapy use (OR = 0.26, 95% CI: 0.17-0.41, p = 0.000). CONCLUSION: In Colombia, there is a predominance of UC over CD (3.9:1), as occurs in other Latin American countries. Patients with extensive UC, severe UC, or CD with noninflammatory disease behavior (B2, B3) have a worse prognosis.

Flow cytometry, a useful tool for detecting the lethal effect of pentamidine on Leishmania viannia complex promastigote forms.

Flow cytometry (FC), combined with propidium iodide as supravital colorant, was used to study Leishmania(subgenus Viannia)panamensis [L (V) panamensis] complex strain susceptibility to meglumine antimoniate, sodium stibogluconate and pentamidine. Despite all drugs examined being leishmanicidal to axenic forms in in vitro trials (in the presence of macrophages), axenic amastigotes directly exposed to these drugs were highly resistant under our experimental conditions. A direct lethal effect on promastigotes, detectable by FC, was only obtained with pentamidine after in vitro treatment of both promastigotes and axenic amastigotes with the drugs. Pentamidine's rapid lethal effect, as detected by FC, could be further confirmed in short- and long-term parasite cultures after exposure to a drug. FC's suitability for measuring L (V) panamensis complex's promastigote susceptibility to pentamidine, shortly after in vitro drug exposure, might be useful in monitoring clinical trials with this drug and facilitating rapid pentamidine-resistant natural isolate identification.

Cultivation and characterization of stable Leishmania guyanensis complex axenic amastigotes derived from infected U937 cells.

The study of the differential regulation of several genes, in both Leishmania parasite life cycle forms, has been simplified by the development of in vitro axenic amastigote culture. Different reports have described extracellular amastigote production and maintenance from several Leishmania spp. A general approach to induce amastigote-like transformation includes progressive pH and temperature changes. Production of axenic amastigotes in continuous cultures using amastigotes recovered from macrophages is described in this report. Leishmania (Viannia) panamensis (M/HOM/PA/71/LS94) and Leishmania (V). guyanensis (M/HOM/BR/75/M4147) intracellular amastigotes were recovered from the human macrophage-like U937 cell line previously infected with promastigotes. The parasites were immediately adapted for growth and kept as axenic amastigotes at 34 degrees C and acidic pH. These organisms were able to infect macrophage cell lines, maintain amastigote morphologic features, and express stage-specific transcripts. The relevance of axenic amastigotes in characterizing virulence factors in American leishmaniasis is discussed.

Leishmania: fine mapping of the Leishmanolysin molecule's conserved core domains involved in binding and internalization.

The Leishmanolysin molecule's role in the uptake of Leishmania parasites by the human U937 pro-myelocytic cell line was studied, using synthetic peptides representing the complete Leishmania (Viannia) guyanensis Leishmanolysin protein amino acid sequence. The particular peptides present in two protein's core domains efficiently impaired the internalization of promastigotes from four different Leishmania species and modified the kinetics of the binding of heterologous recombinant Leishmanolysin protein. The functional domains which exhibited this property represent a highly conserved portion of the sequence among different Leishmania species. The peptides' inhibitory activity correlated with their ability to bind molecules present on the surface of the human cell line. One of the two functional core domains identified involves the previously described adhesive sequence (SRYD) and the putative zinc-binding motif (HExxH). The second functional core domain includes a third histidine residue coordinated with zinc which determines the molecule's structural features. These findings indicate that the molecular interactions between Leishmanolysin's conserved domains and the macrophage surface molecules efficiently contribute to the parasite's internalization. Induction of neutralizing immune responses, which impair the early parasite-host interaction described here, may be an important alternative in designing synthetic subunit human leishmaniasis vaccines.

Lesiones pulmonares en necropsias de consumidores de cocaina / Pulmonary injuries in necropsy of cocaine consumers

Esta investigación se propuso como objetivo general, establecer las lesiones pulmonares más comunes que se encuentran en las necropsias de occisos con antecedentes de adicción a la cocaina y bazuco. Fueron materiales básicos para la investigación los protocolos de las necropsias realizadas desde el primero de junio a 31 de diciembre de 1995 y las muestras patológicas de pulmón para establecer el tipo de lesión. Metodológicamente, se procedió de la siguiente forma: se seleccionaron 30 casos de 300 necropsias que cumplieran ciertas características tales como no poseer documento de identificación y quemadura de los pulpejos entre otras, donde se obtuvieron datos demográficos, manera de muerte y resultados de laboratorio previa su elaboración de instrumento. Los estudios de histopatología fueron realizados por patólogos del INME con tinciones de hematoxilina-eosina. Entre los resultados más sobresalientes podemos señalar que las lesiones más frecuentes encontradas fueron la ruptura alveolar con un 91.7 y la neumonitis intersticial un 90.2, así como hiperplasia alveolar, necrosis bronquial, metaplasma escamosa y trombosis arterial, los cuales se presentaron con menor frecuencia y no son descritos en la literatura internacional. Finalmente destacamos como conclusión que en nuestro medio los consumidores de bazuco presentan lesiones histopatológicas similares a las descritas en los consumidores de crack