Use of liver grafts from anti-hepatitis B core-positive donors: a multicenter study in Argentina.

Liver transplantation success is limited by the availability of donors. To overcome this limitation, anti-core-positive donors are increasingly being accepted, but underutilization of this resource still occurs. We performed the current study to determine the prevalence of anti-core-positive donors in our region and to describe the management of these donors and their recipients. Between January 2005 and July 2011, the national transplant database included 2,262 registered liver donors among whom 106 (4.7%) were anti-core-positive including 59 (56%) discarded and 47 (44%) implanted organs. A median of 14.5 offers (range 4-60) were rejected before harvesting and implanting the accepted grafts. The only difference between the implanted and the discarded grafts was found for the alanine aminotransferase level, which was higher among the discarded ones (50 ± 59 UI/L vs 25 ± 16, P < .05). Among 40 recipients included in the study, 5 (12.5%) did not receive any prophylaxis; 18 (45%) a nucleos(t)ide analog 11 (25.5%), heptitis B immunoglobulin and nucleos(t)ide analogs and 6 (15%) pretransplant hepatitis B vaccination. Over a mean follow-up of 871 ± 585 days, 4 de novo hepatitis B cases were identified at 545, 720, 748, and 1,080 days posttransplantation. None of these patients had received any prophylaxis. In all cases entecavir successfully controlled viral replication. We believe that better utilization of these donors and careful management of their recipients represent safe strategies to expand the liver donor pool in Argentina.

Indicadores hematológicos y hemoquímicos de Dasyprocta fuliginosa (guara, guatín o ñeque) en cautiverio / Hemochemical and haematologic Indicators in Dasyprocta fuliginosa (guara, guatín o ñeque) In captivity

Los indicadores hematológicos y hemoquímicos de la Dasyprocta fuliginosa (guara, guatín o ñeque) en cautiverio se realizaron en el municipio de Florencia, Caquetá (Colombia), pretendiendo iniciar una referencia de datos para estudios de conservación, manejo productivo y clínico de la especie. Fueron utilizados diez animales machos en dos estados de desarrollo (juveniles y adultos). Para hemograma se determinaron hematocrito (técnica de microhematocrito),hemoglobina (método espectrofotométrico de la cianometahemoglobina), recuento total de leucocitos (técnica del hemocitómetro) y recuento diferencial de leucocitos (frotis sanguíneo coloreado), y en hemoquímica se determinó glicemia (método GOD-PAP), colesterol(método CHOD-PAP), triglicéridos (método GPO-PAP), proteínas totales (método Biuret) y creatinina (método colorimétrico simétrico). Los valores promedios para los parámetrosevaluados en hemograma fueron: hematocrito 49,9 ± 2,9 por ciento; hemoglobina 16,5 ± 1,1 g/dl; recuento leucocitario total 6650 ± 1276,9 leucocitos/mm3; neutrófilos 17,7 ± 12,9 por ciento; linfocitos 77,6 ± 12,4 por ciento, y eosinófilos 5,1 ± 3,2 por ciento. Para hemoquímica los resultados fueron: glicemia 249,9 ± 47,1 mg/dl; colesterol 108,1 ± 20,1 mg/dl; triglicéridos 108,1 ± 20,1 mg/dl, proteínas totales 5,7 ± 0,6 g/dl, y creatinina 1,7 ± 0,2 mg/dl. En algunos individuos los valores se desviaron significativamente del promedio, debiéndose tal vez a circunstancias fisiológicas e individuales (estrés, respuesta a mecanismos externos)o por lesiones que padecían días antes a la toma de la muestra. Los indicadores del hemograma estuvieron en promedios similares a los de otros roedores del piedemonte amazónico: Proechimys sp., Agouti paca e Hydrochaeris hydrochaeris, al igual que en los hemoquímicos, salvo en glicemia, en donde se encontraron mayores valores para Dasyprocta fuliginosa, debido posiblemente al régimen alimenticio que se basaba sobre todo en frutas y subproductos de cocina...

GFRalpha3 is expressed predominantly in nociceptive sensory neurons.

Activation of the RET receptor tyrosine kinase by glial-derived neurotrophic factor family members is dependent on a family of coreceptors, GFRalpha1-4. GFRalpha3 preferentially binds the newest member of the glial-derived neurotrophic factor family of ligands, artemin. The major site of GFRalpha3 expression is in the dorsal root ganglion; however, the class of sensory neurons that expresses GFRalpha3 has not been reported previously. Using immunohistochemical methods, we show that the majority of dorsal root ganglion cells that express GFRalpha3 also express vanilloid receptor type 1, peripherin, RET, trkA and calcitonin gene-related peptide. In addition, a significant subpopulation of GFRalpha3-expressing cells also binds the lectin IB4. We demonstrate that GFRalpha3 artemin neurons are immunopositive for markers expected of nociceptors and include a subset of neurons distinct from the GDNF-responsive population. Our results indicate artemin may exert selective effects on pain sensation.

Perturbation of RET signaling in the embryonic kidney.

We have used a RET-Ig fusion protein to disrupt signaling in the rat embryonic kidney development pathway. Treatment of embryonic kidney organ cultures with RET-Ig results in a decrease in branching of the ureteric bud and a down regulation in expression of the Wnt-11, Wnt-4, and ld genes. These data suggest that Wnt-11, Wnt-4, and ld function downstream of RET signaling in normal development. Expression of BMP-7, shh, and ptc were uneffected by RET-Ig treatment, implying that these genes are regulated independently of ret. We have also performed immunohistochemistry with a GFR alpha-1 specific polyclonal antisera to localize GFR alpha-1 protein expression in the developing kidney.

Nutritional and immunologic evaluation of patients with gastric cancer before and after surgery.

The main objective was to evaluate a patient's immunologic and nutritional status as a prognostic indicator of morbidity and mortality in patients with gastric cancer. A prospective clinical study carried out at the National Cancer Institute in Bogotá, Colombia. Our study group consisted of 40 patients with a diagnosis of gastric adenocarcinoma that was treated surgically. Blood samples were taken before and 5 d after surgery; mononuclear cell typing was done by flow cytometry allowing a bicolor analysis. Nutritional evaluation was obtained through measurement of albumin levels, average weight loss, and nutritional risk index (NRI). Half of the malignancies were localized to the middle and lower third of the stomach: stage I, 17.55%; stage II, 10%; stage III, 55%; and stage IV, 17.5%. Twenty subtotal gastrectomies, 11 total gastrectomies, 7 gastrojejunostomies, and 2 esophagogastrectomies with D1 and D2-D3 lymph node resection were performed. A postoperative morbidity of 22.5% and a mortality of 7.5% were observed. A preoperative cellular immunosuppression was identified, with a helper lymphocyte (CD4) to suppressor/cytotoxic lymphocyte (CD8) ratio of 1.38 normal value (NV > 1.5), which increased according to the stage of the disease. Patients who died presented with a significantly greater preoperative cellular immunosuppression than those who survived (P = 0.05). Postoperative mortality correlated significantly with hypoalbuminemia (P = 0.008). In those who died, weight loss was greater than in those who survived (P = 0.06). Patients with severe malnutrition had greater postoperative mortality according to the NRI. Severe preoperative cellular immunosuppression (CD4/CD8 < 1), hypoalbuminemia, weight loss, and severe NRI have a positive predictive value for mortality in patients with gastric cancer.

Expression of Radical fringe in limb-bud ectoderm regulates apical ectodermal ridge formation.

The apical ectodermal ridge of the vertebrate limb bud lies at the junction of the dorsal and ventral ectoderm and directs patterning of the growing limb. Its formation is directed by the boundary between cells that do and cells that do not express the gene Radical fringe. This is similar to the establishment of the margin cells at the Drosophila wing dorsoventral border by fringe. Radical fringe expression in chick-limb dorsal ectoderm is established in part through repression by Engrailed-1 in the ventral ectoderm.

[Blood erythropoietin levels in healthy subjects studied in the valley of Mexico]. / Niveles séricos de eritropoyetina en sujetos sanos estudiados en el valle de México.

Erythropoietin (EPO) is the hematopoietic growth factor that regulates red cell production. There is a direct relationship between its secretion and tissue hypoxia. Above sea level, oxygen concentration diminishes. This causes an increase of hemoglobin and hematocrit; this effect could be the consequence of higher EPO levels. Currently, evaluation of baseline serum EPO levels is very important in the differential diagnosis of anemia and erythrocytosis. The purpose of the present work was to report the EPO levels on a group of healthy blood donors living in Mexico City, 2,240 m above sea level. Two-hundred twenty blood donors were selected to measure serum EPO; there were 168 males and 52 females. Median EPO levels of the entire population were 7.5 mU/mL (percentile interval, PI, 1-18). Median EPO levels were 7.6 (PI 1-18) and 7.5 (PI 1-16.9) for men and women, respectively. We did not find differences in serum EPO levels among previous reports in other populations and the values determined in this study.

Structural diversity in the extracellular faces of peptidergic G-protein-coupled receptors. Molecular cloning of the mouse C5a anaphylatoxin receptor.

The mouse C5a receptor gene was isolated using the human C5a receptor cDNA probe recently described (Gerard, N. P., and C. Gerard. 1991. Nature 349:614). By analogy with the human gene, the mouse homolog contains two exons with the 5' untranslated region and initiating methionine codon present in exon 1 and the remainder of the molecule in exon 2. Generation of an expressible cDNA for the mouse C5a receptor was accomplished using the polymerase chain reaction and a sense oligodeoxynucleotide primer which included an initiation codon just 5' to the sequence encoding the N-linked glycosylation site. When transfected into human 293 kidney epithelial cells the cloned cDNA directs expression of a binding site for human C5a anaphylatoxin with a binding constant of 2.5 +/- 0.3 nM; the human C5a receptor expressed under identical conditions has a Kd of 1.7 +/- 0.2 nM. Overall, the deduced amino acid sequences of the receptors are 65% identical given the analogous gene structures. Alignment of the sequences as seven transmembrane segment receptors reveals that the greatest structural diversity (approximately 70%) exists in the putative extracellular domains. In contrast, species differences among other members of this family of seven membrane-spanning receptors is generally only 10 to 20%, even for receptors whose ligands are relatively small and not expected to interact with sites on the extracellular surfaces. A high degree of structural identify is observed for the C5a receptors in the transmembrane segments and in all but one of the loops predicted to exist in the cytoplasm. Inasmuch as critical structures responsible for high affinity binding of the 74 amino acid polypeptide to both C5a receptors involve features conserved between species, these data provide the starting point for mutagenesis studies to determine the nature of the binding and activation sites for the chemotactic receptors. Additionally, these data provide a reagent for immunologic and molecular genetic studies on the role of C5a receptors in inflammatory models.

Identification of B- and T-cell epitopes within the MTP40 protein of Mycobacterium tuberculosis and their correlation with the disease course.

Synthetic peptides derived from the amino acid sequence of MTP40, a recently characterized Mycobacterium tuberculosis protein, were tested by two different immunological assays in 91 individuals. For the purposes of this study, the population was distributed in four groups: active tuberculosis (TBC) patients with elevated bacillus loads (BK+), active TBC patients with low bacillus loads (BK-), healthy individuals living in the same household with tuberculous patients (HH), and normal individuals, who had presumably never been in contact with the bacilli (control). We found that T cells of individuals belonging to the HH group showed the highest and most frequent recognition of these peptides in a T-cell proliferation assay, while their antibodies showed the lowest recognition of these peptides when tested by enzyme-linked immunosorbent assay. In contrast, TBC patients revealed an inverse pattern of immune response. Interestingly, one of these peptides (P7) was recognized by T cells of 64% of the HH individuals and by 4.5% of normal donors. Another peptide (P4) was recognized by 55% of sera from BK+ patients and by 5.5% of normal donors. The results presented here indicate the existence of T- and B-cell epitopes within the MTP40 protein. Given the particular recognition pattern of this protein, added to the fact that it appears to be a species-specific antigen of M. tuberculosis, a detailed study of the immune response to it may be useful in the design of more accurate diagnostic tests and an improved vaccine against human TBC.

Specific and sensitive immunological diagnosis of Chagas' disease by competitive antibody enzyme immunoassay using a Trypanosoma cruzi-specific monoclonal antibody.

Coexistence of Chagas' disease with leishmaniasis and T. rangeli infection in endemic areas and cross-reactivity between corresponding etiological agents can confuse the immunodiagnosis of Chagas' disease. A discriminative serological test could therefore represent a major advance in specific immunodiagnosis. A competitive antibody enzyme immunoassay against a component 5-enriched preparation, using a T. cruzi species-specific monoclonal antibody has allowed development of a specific serodiagnosis of Chagas' disease with high sensitivity (96.6% in undetermined and chronic phases of infection). This test can differentiate Chagas' disease from other cross-reacting parasitic diseases in areas where concomitant infections are unknown or suspected.

Different monoclonal antibodies against the component 5 specific for Trypanosoma cruzi.

Three murine monoclonal antibodies (I-35/67, II-190/30, III-160/18) produced by immunization against total epimastigote extract or component 5-enriched fractions of Trypanosoma cruzi (Tehuantepec strain) have been demonstrated to recognize the component 5 specific for T. cruzi. By immunofluorescence studies, one of these monoclonal antibodies (I-35/67) was shown to bind to the epimastigote cell surface, and the two others (II-190/30 III-160/18) were preferentially directed against internal subcellular organelles. Immunoprecipitation using these monoclonal antibodies followed by SDS-PAGE analysis, has led to identification of four molecules with apparent molecular weights of 72 Kd, 51 Kd, 43 Kd, and 24 Kd in T. cruzi epimastigotes. Potential uses of these monoclonal antibodies in serological tests and immunochemical analysis of target antigens are discussed.

[Production of monoclonal antibody anti-antigen 5 for Trypanosoma cruzi]. / Production d'un anticorps monoclonal anti-antigène 5 de Trypanosoma cruzi.

Monoclonal antibodies against Trypanosoma cruzi have been produced by fusion of Sp 2/0 myeloma cells and splenic lymphocytes from BALB/c Mice immunized with a T. cruzi antigenic fraction. Antigenic studies of these monoclonal antibodies have led to the identification of IgG 1 antibody against the component 5 specific for T. cruzi (cellular clone II 190/151). These monoclonal antibodies will give rise not only to new diagnostic and epidemiological perspectives but will also aid in achieving a better understanding of the biological role of this antigen.

Educacion y capacitacion para la participacion de la comunidad en el programa de abastecimiento de agua potable y saneamiento rural de Colombia. / Education and training for communitary participation in rural water supply and sanitation program in Colombia

En este articulo se informa del desarrollo del Programa de Abastecimiento de Agua Potable y Sameamiento Rural de Colombia, que incluye un importante componente de participacion de la comunidad el cual se cumple en cinco etapas metodologicas: estudio de la comunidad, preparacion del proyecto, promocion y organizacion de la comunidad, construccion de la obra y administracion de la obra y administracion del servicio. Se describen las actividades que comprende cada una de esas etapas y se senalan los resultados sociales y economicos que se han obtenido con la aplicacion de ese enfoque, a saber: cambio de actitud de la poblacion, iniciacion de proyectos comunales rentables, disminucion del exodo rural, desarrollo rural integrado, utilizacion de materiales locales, generacion de empleo, capacitacion de la poblacion, diversion estatal, incentivo artesanal y turistico, etc. Asimismo se incluye informacion sobre las acciones de educacion y capacitacion desarrolladas por el Programa en pro de la participacion de la comunida