Comparación del ordenamiento de predicciones BLUP y la respuesta a la selección en conejos cuando el efecto año-estación se considera fijo o aleatorio / Comparison of the BLUP prediction order and the response to selection in rabbits when the effect yearseason is considered to be either fixed or random

En lineas de conejos reproductivamente cerradas, criadas con generaciones discretas, existe una fuerte asociacion entre el año-estacion (AE) y los niveles de consanguinidad (F). Estudios realizados anteriormente mostraron que, cuando AE y F son considerados como efectos fijos en un modelo, la heredabilidad y la tendencia genetica se sobreestiman. El objetivo del trabajo fue investigar las consecuencias de considerar AE como fijo (M1) o aleatorio (M2) sobre la seleccion de animales. Se utilizaron 15671 registros correspondientes al numero de destetados de la linea A, del Departamento de Ciencia Animal de la Universidad Politecnica de Valencia, España. Los modelos fueron comparados en base a: los ordenamientos de los valores geneticos aditivos estimados en cada generacion y la respuesta esperada a la seleccion. Se plantearon seis escenarios segun intensidades de seleccion. En cada uno se estimo la correlacion de Spearman y se calculo el porcentaje de discordancia (D) entre los animales elegidos por M2 y no por M1. La respuesta a la seleccion para los animales escogidos por M1 o M2, fue estimada como la pendiente de la recta de regresion entre las medias de los valores geneticos predichos por M2 a traves de las generaciones. A medida que disminuyo la presion de seleccion, aumentaron las correlaciones de Spearman, disminuyendo los D. Aunque, a nivel generacion ambos estimadores no mantuvieron siempre la misma relacion. Las respuestas a la seleccion estimadas fueron similares para los animales seleccionados por M1 o M2, con lo cual no se esperan diferencias entre ambos modelos respecto a la seleccion.

In close reproductive lines of rabbits reared in discrete generations, there is a strong association between the year-season (AE) and the levels of consanguinity (F). Previous studies have shown that when AE and F were considered as fixed effects in a model, the heritability and the genetic tendency were overestimated. The objective of this work was to investigate the consequences of considering AE as either a fixed (M1) or random (M2) effect on the selection of animals. A total of 15,671 records corresponding to the number of rabbits weaned in line A, from the Department of Animal Science of the Polytechnic University of Valencia, Spain, were used. The comparison of models was based on the rankings of the estimated additive genetic values in each generation and the expected response to the selection. Six scenarios were proposed, varying in selection intensities. In each one, the Spearman correlation was estimated and the percentage of discordance (D) between the animals chosen for M2 but not for M1 was calculated. The response to selection for the animals chosen by either M1 or M2, was estimated as the slope of the regression line between the means of the genetic values predicted by M2 through generations. As the selection pressure decreased, the Spearman correlations increased, decreasing the D. However, at the generation level, both estimators did not always maintain that relationship. The estimated responses to selection were similar when the selection was based on estimated breeding values obtained by using either M1 or M2. Therefore, no differences are expected between both models with respect to selection.

Caracterización genética de cuatro poblaciones de ovinos criollos de Argentina / Genetic characterization of four populations of Argentinian creole sheep

Los ovinos criollos son los fundadores de la ganadería ovina en la Argentina y han contribuido de manera sostenida al desarrollo económico, social y cultural de algunas regiones del país. A pesar de ello, es un recurso zoogenético escasamente valorizado y por ende poco estudiado. En orden de caracterizar genéticamente a los ovinos criollos argentinos, se tomaron muestras de ADN de cuatro poblaciones representativas localizadas en las provincias de Buenos Aires, Corrientes, Santiago del Estero y Salta. Estas majadas se seleccionaron por ser grupos conservados, que presentan las características fenotípicas de la raza y no registran la introducción de animales de otras razas en el sistema de reproducción. Un total de 30 marcadores microsatélites y la región D-loop del ADN mitocondrial fueron analizados. El análisis de los microsatélites permitió evidenciar una alta diversidad genética intrapoblacional (Ho= 0,676; He= 0,685; PIC= 0,713). Dicha variabilidad es explicada por diferencias entre los patrones moleculares de los individuos estudiados que pueden clasificarse en 3 grupos de poblaciones significativamente diferentes: BA, SA, SE+CO. Dado que dichas poblaciones explican muy poco de la variabilidad total (7,6%), ellas deberían considerarse perteneciente a una misma raza. El análisis del D-loop mitocondrial demostró que los individuos analizados están relacionados con el haplogrupo asiático, el cual está ampliamente distribuido en las razas españolas que son las antecesoras de la raza criolla argentina. Los resultados obtenidos en este trabajo proveerán información para establecer criterios de manejo de este recurso genético de Argentina con el fin de implementar planes de conservación, recuperación y/o mejora de los programas.

Creole sheep are the founders of sheep farming in Argentina and have contributed in a sustained way to the economic, social and cultural development of some regions of this country. However, it is a scarcely valorised and poorly studied genetic resource. In order to genetically characterize the Argentinian Creole sheep, DNA samples were taken from four representative populations located in the provinces of Buenos Aires, Corrientes, Santiago del Estero and Salta. These flocks were selected because they are considered to be conserved groups, they have the phenotypic characteristics of the creole breed and there are no records about the introduction of animals of other breeds into those systems. A total of 30 microsatellites and the D-loop region of mitochondrial DNA were analysed. Microsatellite analysis showed high level of genetic diversity within populations (Ho= 0.676; He= 0.685; PIC= 0.713). This variability is explained by differences between molecular patterns of the studied individuals, which can be classified into three significantly different population groups: BA, SA, SE+CO. Since these populations explain very little of the total variability (7.6%), it can be considered that they belong to a same race. The analysis of the mitochondrial D-loop showed that Argentinian Creole sheep have haplotypes belonging to the Asian haplogroup, which is widely distributed in the Spanish breeds, which are considered to be their ancestors. The results obtained in the present study will provide information to develop management criteria for this genetic resource in Argentina, in order to implement their conservation, recovery and/or to develop breeding programs.

Genetic relationships among American donkey populations: insights into the process of colonization.

This study presents the first insights into the genetic diversity and structure of the American donkey metapopulation. The primary objectives were to detect the main structural features underlying variability among American donkey populations, identify boundaries between differentiated gene pools, and draw the main colonization pathways since the introduction of donkeys into America in the 15th century. A panel of 14 microsatellite markers was applied for genotyping 350 American donkeys from 13 countries. The genetic structure of this metapopulation was analysed using descriptive statistics and Bayesian model-based methods. These populations were then compared to a database containing information on 476 individuals from 11 European breeds to identify the most likely ancestral donor populations. Results showed the presence of two distinct genetic pools, with confluence of the two in Colombia. The southern pool showed a unique genetic signature subsequent to an older founder event, but lacked any significant influence of modern gene flow from Europe. The northern pool, conversely, may have retained more ancestral polymorphisms and/or have experienced modern gene flow from Spanish breeds. The Andalusian and, to a lesser extent, the Catalan breeds have left a more pronounced footprint in some of the American donkey populations analysed.

Genetic characterization of Latin-American Creole cattle using microsatellite markers.

Genetic diversity in and relationships among 26 Creole cattle breeds from 10 American countries were assessed using 19 microsatellites. Heterozygosities, F-statistics estimates, genetic distances, multivariate analyses and assignment tests were performed. The levels of within-breed diversity detected in Creole cattle were considerable and higher than those previously reported for European breeds, but similar to those found in other Latin American breeds. Differences among breeds accounted for 8.4% of the total genetic variability. Most breeds clustered separately when the number of pre-defined populations was 21 (the most probable K value), with the exception of some closely related breeds that shared the same cluster and others that were admixed. Despite the high genetic diversity detected, significant inbreeding was also observed within some breeds, and heterozygote excess was detected in others. These results indicate that Creoles represent important reservoirs of cattle genetic diversity and that appropriate conservation measures should be implemented for these native breeds in order to minimize inbreeding and uncontrolled crossbreeding.

Use of C-reactive protein as a predictor of chorioamnionitis in preterm prelabour rupture of membranes: a systematic review.

BACKGROUND: Studies examining the use of C-reactive protein (CRP) as a predictor of chorioamnionitis in preterm prelabour rupture of membranes (PPROM) report highly conflicting results. Despite this, CRP is commonly used for the early diagnosis of chorioamnionitis. OBJECTIVE: To determine the diagnostic accuracy of CRP in the detection of chorioamnionitis in women with PPROM. DESIGN: Systematic review. SEARCH STRATEGY: Studies were identified from MEDLINE (1966-2006), EMBASE (1974-2006), PubMed and the Cochrane Library (2005) and from reference lists from primary studies and reviews. SELECTION CRITERIA: Only studies of good methodological quality that evaluated the diagnostic performance of CRP in chorioamnionitis in women with PPROM were selected. DATA COLLECTION AND ANALYSIS: Positive and negative likelihood ratios (LR) and diagnostic odds ratios (DOR) were calculated. An attempt was made at pooling data for meta-analysis, but this was considered inappropriate due to the significant unexplained heterogeneity between studies. MAIN RESULTS: There were eight primary studies comprising 610 cases which met the inclusion criteria. There was wide variation in the positive and negative LR and DOR between the studies, with significant lack of precision demonstrated by wide confidence intervals. Three of the studies concluded that CRP was a useful diagnostic tool for chorioamnionitis (DOR ranging from 4.2 to 191.6), although one of them suggested a higher CRP threshold. The other five studies concluded the opposite (DOR ranging from 1.4 to 17.7). AUTHOR'S CONCLUSIONS: There is no clear evidence to support the use of CRP for the early diagnosis of chorioamnionitis. Further research is required to address the contradictory findings of diagnostic accuracy.

Inflammation, complement, ischemia and amoebic survival in acute experimental amoebic liver abscesses in hamsters.

We have examined the role of inflammatory cells, ischemia and serum complement on the development of acute experimental amoebic liver abscess in hamsters (AEALAH). In hamsters made leukopenic by whole body radiation (800 rad) and daily intraperitoneal glycogen injections, the absence of inflammatory cells and liver tissue damage surrounding the parasites resulted in their rapid (24 h) disappearance from the liver, which showed no lesions. Focal liver ischemia, always present in control AEALAH with inflammation and tissue destruction, was reproduced in radiated hamsters by injection of amoebae mixed with Superdex microspheres, but again in the absence of inflammation, amoebae caused no liver damage and disappeared in 24 h. In hamsters made hypocomplementemic by injection of purified cobra venom factor (CVF), amoebae caused AEALA indistinguishable from controls, but in leukopenic + hypocomplementemic hamsters, amoebae were unable to produce lesions and disappeared from the liver in 48 h. We conclude that inflammation and tissue damage are required for the survival of amoebae in AEALAH and for the progression of the experimental disease.

Patagonian Argentine Creole cattle polymorphism: comparison with North-West populations of this breed.

The relict Patagonian Argentine Creole cattle population consist of a small feral population (Los Glaciares population) that is geographically isolated in the South-West of Patagonia. In order to determine the level of genetic variability of this population, the polymorphism of eight structural genes and two microsatellites loci were studied using the polymerase chain reaction (PCR). In addition, genetic characterisation was used to compare Los Glaciares population and the ACc breed of cattle. Results obtained in this study show that the value of average heterozygosity of the studied loci for the Los Glaciares were not significantly different from the ACc. Furthermore, the data of this report were consistent with the hypothesis that Los Glaciares originated from ACc brought to the area by colonialists in the last century. Such data may be useful in formulating management plans for Feral Patagonian Creole cattle populations.

Effect of stress on the Schultz-Dale reaction in guinea pig aorta.

The smooth muscle of thoracic aorta from guinea pig sensitized with egg albumin (EA) produced an anaphylactic contraction when it was exposed to EA. Experiments were performed to evaluate stress effects on the anaphylactic contraction in guinea pig aortic rings. Two types of stressors were used as immunosuppressor stimuli: physical restraint and shaking of the animals. Both stressors diminished the amplitude of the Schultz-Dale contraction in aortic rings from sensitized guinea pig. The shake stress stimulus interrupted several times during each session induced higher immunosuppression in animals in which the active sensitization and the stress sessions began the same day. Severe restraint stress, prior to active immunization, also suppressed significantly the anaphylactic response. The Schulz-Dale reaction in guinea pig aorta seems to be a valuable technique to study the stress effects on the anaphylactic response.

Comparison of 2D- and 3DFT multiple overlapping thin-slab acquisition TOF MR angiography in carotid disease.

We intended to compare two-dimensional Fourier transform (2DFT) with three-dimensional Fourier transform (3DFT) multiple overlapping thin-slab acquisition (MOTSA) time-of-flight (TOF) magnetic resonance angiography for percent diameter stenosis, length of stenosis, and apparent occlusion at the carotid bifurcation. For that, 101 symptomatic patients (n = 202 carotid bifurcations) were evaluated with 3DFT MOTSA TOF and 2DFT TOF. Three observers measured the percent diameter stenosis from oblique axial multiplanar reformatted (MPR) images and length of stenosis from maximum intensity projection (MIP) images. Kappa analysis assessed interobserver agreement and the Wilcoxon signed rank test was used to compare the two MR angiographic techniques. There was a significant difference in the percent diameter stenosis (p < 0.01) and length of carotid stenosis (p < 0.01) between 2DFT and 3DFT MOTSA TOF magnetic resonance angiography. Stenosis was greater in 33% of carotid arteries and was upgraded (NASCET) in 17% of carotid arteries on the 2DFT TOF. The number of apparently occluded carotid arteries was equal with both MRA techniques. There was good agreement between the three observers (k = .50).

[Effect of tobacco combustion on the immunochemical properties of albumin]. / Efecto de la combustión del tabaco en las propiedades inmunoquímicas de la albúmina.

During tobacco burning smoker to run up substances to contain smoke as far as pulmonary tissue that is damage. In cigarette 600 degrees C are in ignition extreme, but in the other side, in contact with edge of the mouth smoker, the temperature is lower. Smoke could be delivery tobacco products until respiratory tract when temperature gradients occur in cigarette burn. For demonstration of the immunoreactive substances in tobacco smoke condense (TSC) we used a model with two cigarette arrangements: several concentrations of bovine seric albumin (BSA) applied to experimental group of cigarettes and phosphate-saline solution (PBS), 0.15 M pH 7.5 without protein to control cigarettes. Both series, experimental and control, remained at 20 degrees C during 48 h, soon afterward TSC was obtained. Higher protein concentration was observe in the experimental TSC of cigarettes expose to more elevated quantities of BSA, this was identify with polyclonal antibodies toward BSA employing counter-immunoelectrophoresis, immunoelectrophoresis, radial immunodiffusion and hemagglutination inhibition test. In summary: TSC of treat cigarettes had a little quantity of protein (BSA), but immunochemical properties of BSA in TSC were preserve because polyclonal antibodies against BSA bind to this protein. In habitual smoker some compounds present in cigarette smoke could be induce an immune response due to immunogen in tobacco substances.

Insular cortex lesions impair the acquisition of conditioned immunosuppression.

Conditioned immunosuppression can be readily obtained in animals by associating a taste with an immunosuppressive drug. On subsequent exposure to the conditioned taste, the animals show an attenuated immune response and also exhibit a conditioned taste aversion. It has been established that insular cortex lesions disrupt the acquisition of conditioned taste aversion. The effect of NMDA-induced lesions in either the insular cortex or the parietal cortex of male Wistar rats was evaluated in the acquisition of conditioned immunosuppression in two experiments. Unlesioned control rats showed the conditioned immunosuppressive response after reexposure to the taste, as indicated by lower hemagglutinating titers to sheep red blood cells in the first experiment and by a decreased IgM production to ovalbumin, measured by ELISA, in the second experiment. Insular cortex-lesioned rats did not show the conditioned immunosuppression in either experiment, while parietal cortex lesions and the sham-lesioned animals presented a clear decrease of hemagglutinating titer and a low IgM production. The insular cortex lesions did not affect the normal immune response, showing normal hemagglutinating titers and IgM production when compared to nonconditioned controls. The immunosuppressive action of cyclophosphamide also remained unaltered. In conclusion, these results show that the insular cortex is essential for the acquisition of conditioned immunosuppression.

[Cytotoxicity caused by tobacco]. / Citotoxicidad inducida por el tabaco.

Condensed smoke (CS) at as concentration of 0.40 mg/ml as well as urethane at 5.0 mg/ml reduced cell adherence and proliferation at percentages lower than 30 and 15% respectively. Control cells displayed 100% adherence and proliferation. Tobacco extract (TE) at 16 mg/ml inhibited cell proliferation in 65%, at 0.75 mg/ml or lower doses results were similar to control cultures and 0.1 mg/ml cell proliferation increases by 15 to 40% above controls. Urethane at 0.10 mg/ml to 0.30 mg/ml to 0.30 mg/ml favored cell proliferation by 55% above control. CS at 0.05 to 0.10 mg/ml presented similar adherence and proliferation results as control cells. MDCK cells treated with ethylenemethanesulphonate and subsequently expanded under normal conditions were incubated with CS, TE and urethane at different concentrations. Their behavior was similar to control MDCK cells. Cell cultures incubated for 3 days after their exposure to CS (0.05 mg/ml) or urethane (2.5 mg/ml) showed 50% inhibition of proliferation when compared to controls. Data obtained in this study indicate that high doses of PDCT are cytotoxic which is reflected in the inhibition of cell adherence and proliferation while low doses of PDTC stimulate these cellular phenomena.

[Smoking. Changes produced by urethane on macrophage receptors and the complement system]. / Tabaquismo. Alteraciones producidas por el uretano en los receptores de macrófagos y el sistema del complemento.

The present of communication result of the analysis action urethane, that is yield of burning tobacco, provoked alterations on macrophages, complement system and red blood cells. Our data show that urethane high concentration kill macrophages and red blood cells and severely inhibits complement activity. These findings suggest that urethane high concentrations injury to macrophage's receptors, complement system and red blood cells and these are associated with pathologic process related with passively and actively smoking individuals.

[Immunoglobulin A and tobacco antigens in patients with pneumopathy]. / Inmunoglobulina A y antígenos del tabaco en pacientes neumópatas.

Smoking is an addiction related with several cardiopulmonary diseases. Some compounds derived from tobacco combustion can be induce a response of secretory immune system, because antigen penetration is by respiratory tract epithelium, with IgA antibodies synthesis and immune complex (IC) generation. Seric anti-tobacco antibodies were showed in 44% of healthy smokers and 71% of non-smoker. In 56% of smokers and 38% at non smokers were found IC with 0.19 and 0.15 mg/ml of IgA respectively. Molecular weight of IC constituents were between 12 and 80 Kd. Sera were without free tobacco antigen. Pneumopathic patients had anti-tobacco antibodies in 100% of them and positive IC in 72% of smokers and 65% of non-smokers. IgA concentration in CI was 1.41 and 1.26 mg/ml respectively. Molecular weight of IC compounds were from 14 to 90 Kd. Free tobacco antigen in serum was observed in 44% of smokers and 41% of non-smokers pneumopathic patients. We concluded that patients with lung disease had higher frequency of anti-tobacco antibodies and IC, further IgA concentration in IC was higher and free tobacco antigen present in pneumopathic sera comparing with healthy people. The presence of circulating IC with IgA antibodies and the potential inductive influence of tobacco products in these entities, should provide an energetic stimulus to search the role of tobacco antigens in pulmonary inflammatory diseases.

Comparison of Clostridium sordellii toxins HT and LT with toxins A and B of C. difficile.

Clostridium sordellii produces two toxins, designated HT (haemorrhagic toxin) and LT (lethal toxin), that are similar to toxins A and B of C. difficile. The physicochemical properties of toxins HT and A were remarkably similar. The specific biological activities of toxin HT were almost the same as those of toxin A, and their NH2-terminal sequences shared close homology. The properties of toxins LT and B were similar, as were their NH2-terminal sequences, but toxin B was much more cytotoxic than toxin LT. Immunodiffusion analysis with specific antibodies showed that although toxins B and LT shared major antigenic determinants, each had unique epitopes. The results suggest that toxins B and LT have diverged more than toxins A and HT. Immunoblotting with antibodies to the toxins of C. difficile showed that toxins HT and LT had common antigenic determinants.

Pathogenesis of acute experimental amebic liver abscess in hamsters.

The hypothesis was tested that tissue necrosis in acute experimental amebic liver abscess in hamsters is not caused directly by the parasite but rather, indirectly, by the destruction of closely surrounding leukocytes that release their lysosomal enzymes and damage neighboring liver cells. Axenically grown trophozoites of Entamoeba histolytica strain HM-1 were injected intraportally into normal, hypocomplementemic, and leukopenic hamsters, and the lesions were studied histologically 2, 5, 10, and 24 hr after injection. Hypocomplementemia (less than 5% of normal CH50) and leukopenia (less than 1,000 leukocytes/ml) were achieved and sustained for up to 72 hr with repeated intraperitoneal injections of goat anti-hamster C3 and anti-hamster leukocyte antibodies, respectively. Decrease or absence of polymorphonuclear leukocytes in the vicinity of intrahepatic amebas effectively blocked deleterious effects of the parasites on surrounding hepatocytes. We conclude that in acute experimental amebic liver abscess the direct effect of the parasites on hepatocytes and their stroma is not responsible for tissue necrosis, but rather it is due to their indirect action through the destruction of inflammatory cells.

[Characterization of the desmoglein in renal cells in culture]. / Caracterización de la desmogleína de células renales en cultivo.

Desmosome junctions are found in epithelial tissues. They both link cells externally and anchor cytoplasmic intermediate filaments to the plasma membrane. Quantitative and qualitative abnormalities in intercellular junctions have been described in a broad spectrum of human and animal cancers. Current efforts are aimed at exploring the possibility that some of these defects may account for the hallmarks of malignancy, namely tumour invasion and metastasis. Desmosomes are constituted by several proteins, one of them is desmoglein-1 (DG-1), a transmembrane glycoprotein who glycosylated portion is major component of the adhesion mediating desmoglia. In order to know the similarity between tissue DG-1 and cultured renal cells DG-1 was used antisera raised against DG-1 to identify cross-reacting components. Anti DG-1 antibodies stained cell-cell boundaries in a punctate fashion in epithelial tissue and on densely grown monolayers of renal cells. Radioimmunoprecipitation and immunoelectrotransference show positive reaction with anti DG-1 antibodies with desmosomes obtained from epithelial tissue and renal cells monolayers, but last one was less positive. Results suggest some minor differences between DG-1 extracted from diverse sources but they have a commun immunodominant epitope.

Evidence that G-CSF is a fibroblast growth factor that induces granulocytes to increase phagocytosis and to present a mature morphology, and that macrophages secrete 45-kd molecules with these activities as well as with G-CSF-like activity.

Evidence is provided that conditioned medium from a macrophage-like cell line contains molecules of approximately 45 kd molecular weight with granulocyte colony-stimulating factor (G-CSF)-like activity as well as with the property of inducing granulocytes to phagocytose latex particles and to mature morphologically. This type of differentiation was found to be induced on either bone marrow or induced granulocytes, but not on resident or induced macrophages. On the other hand, resident but not induced macrophages are shown to induce these types of activities when challenged by bacterial lipopolysaccharides. Evidence that macrophages produce a factor that is mitogenic for fibroblasts is also provided. This activity was measured by the induction of increased proliferation by either low-density or saturated cultures of fibroblasts. Human recombinant G-CSF was employed and found also to possess these dual capabilities of inducing both the proliferation and differentiation of granulocytes as well as the proliferation of fibroblasts. Finally, a mechanism for the regulation of myeloid cell production and differentiation is described in which G-CSF produced by macrophages not only induces granulocytes to differentiate but induces fibroblasts to proliferate and secrete macrophage colony-stimulating factor (M-CSF), which in turn makes myeloid monocyte precursors proliferate and secrete more G-CSF.

[The mechanism of natural resistance in the rat to Entamoeba histolytica]. / Estudios sobre el mecanismo de la resistencia natural de la rata a Entamoeba histolytica.

The data presented in this paper may be summarized as follows: 1) intraportal injection of a virulent strain (HM-1) of Entamoeba histolytica in Wistar rats, of both sexes, gives way to non-progressive microscopic changes, characterized by a rapid leukocytic reaction surrounding the amebas, disappearance of the parasites within 5 hours, and total lack of hepatic damage; 2) leucopenia only modifies the previous description by the fact that there are no leucocytes around the amebas, although these disappear in the same time, showing, at this moment, an early and prominent vacuolar degeneration; 3) hypocomplementaemia shows the same results as leucopenia; 4) fragments and extracts from various tissues from the rat and hamster show variable degrees of interference with the viability of axenic amebas of Entamoeba histolytica conserved in culture; only a minimal part of the interference to be due to the activity of the complement which is present in the tissue extracts.

Cytotoxic and proliferative effect of tobacco products on Lewis lung adenocarcinoma cells and spleen lymphocytes.

The effect of tobacco products (TP) on the proliferation of lung adenocarcinoma cells (3LL) and mice spleen lymphocytes as well as on tumor growth and metastasis was analyzed. High concentrations of cigarette smoke condensate (CSC) or tobacco extract (TE) were cytotoxic for tumoral and lymphoid cells; in contrast smaller amounts of TP increased thymidine incorporation in both cell types. Lymphocytes were more susceptible to the toxic effect of TP than 3LL cells. When CSC or TE were mixed with 3LL cells and then inoculated into mice, they did not modify either the size of the local tumor induced by 3LL cells, or the number or appearance time of lung metastasis, although there was an increase in spleen weight.