Th1-type cytokines improve resistance to murine cysticercosis caused by Taenia crassiceps.

Resistance and susceptibility to different parasitic diseases have been associated with the predominance of Th1- or Th2-type immune responses. In experimental murine cysticercosis a Th1 response seems to be involved in resistance, whereas Th2 activity is associated with heavy parasite intensities. To test this notion the roles of Th1- and Th2-type cytokines in infected mice were studied after treatment with anticytokine monoclonal antibodies or with recombinant murine cytokines during early stages of infection. Mice receiving anti-interleukin 10 (IL-10) carried lower parasite intensities than did control mice and developed a strong Th1-type response, whereas mice receiving anti-interferon gamma (IFN-gamma) showed a dramatic increase in susceptibility. Treatment with recombinant cytokines confirmed these results; mice receiving IFN-gamma and IL-2 showed low parasite numbers, whereas IL-10 induced a significant increase in parasite loads. Thus, the Th1-type immune response plays a fundamental role in protection against Taenia crassiceps cysticercosis, whereas Th2, at least through IL-10, favors parasite establishment.

The descrease of the in vitro proliferative response of zinc-treated stressed mice's thymic lymphocytes.

Prolonged stimulation of newborn mice by intraperitoneal injections with inactivated staphylococci induces a chronic neonatal inflammatory reaction and an associated oxidative-stress response. The chronically stimulated animals exhibit anorexy. show a reduction in their body weight and undergo a depression in both antibody synthesis andin vitro proliferativc response of Con A-stimulated splenic T-lymphocytes. These stressed animals also develop adrenal hyperplasia, hypozincamia and thymic hypoplasia. Despite this stress-mediated thymic involution, Con-A stimulated T-lymphocytes from thymus displayed increased theirin vitro proliferative response. Results of the present work show that intramuscular injections of zinc acetate in stressed mice, one single dose (5 microg) every other day for two weeks, reduce both the zinc concentration in the thymus gland and thein vitro proliferative response of their Con A-stimulated T-lymphocytes. The results suggest that prophylactic administration of zinc can have benefical consequences on the immunity of chronically stressed mice.

Stressful stimulation of newborn mice increases the in vitro proliferative response in T cells from thymus.

The effects of prolonged stressful stimulation on the in vitro proliferative response of thymic T cells and the thymic zinc concentration were investigated in newborn Balb/c mice. Animals were stressed by intraperitoneal injections with aliquots from a heat-killed staphyloccocal suspension over one month. The splenic T lymphocytes from the stressed animals showed a significant reduction in the in vitro response to Concanavalin A (Con-A) stimulation. However, an unexpected and significant increase in proliferative response was observed when thymic lymphocytes from stressed animals were stimulated with the same mitogen. The intrathymic zinc levels were regularly elevated in stressed mice, in contrast to those values obtained in the thymus from healthy control mice. These results suggest that neonatal stress can disrupt the intrathymic maturation and the selection of pre-T lymphocytes. The increment of the in vitro proliferative response of T cells from the thymus of stressed mice may be caused by proportionally higher amounts of intrathymic lymphoid subpopulations expressing a mature phenotype and functionality.

Zinc administration prevents wasting in stressed mice.

Experimentally induced chronic stress can produce severe retardation on the physical development of young animals. Moreover, the chronic stress and its associated secondary malnutrition cause a variable depression on immunity, whose pathogenesis has been related to the excessive production of cytokines and glucocorticoids. When stressful stimuli are excessive, animals increment their anorexia and express a progressively installed wasting syndrome, associated with hypozincemia and susceptibility to infections with high mortality rate. In this work, chronically stressed mice were studied to observe the prophylactic effect of a zinc treatment on the evolution of both their malnutrition and their immune competence. Stress was induced in newborn Balb/c mice by intraperitoneal (IP) injections with heat-killed bacteria for 4 weeks. Following this inductive period, almost all the stressed mice showed a transient wasting syndrome characterized by anorexia, deficient gain of corporal weight, diarrhea, skin infection, reduced antibody response against antigens of red blood sheep cells, and a decreased proliferative response in their Con-A stimulated splenic lymphocytes. However, when the stressed mice received an additional IP treatment with zinc acetate, their clinical condition showed a significant improvement and their immunocompetence was similar to that exhibited by non-stressed mice from the control groups. The results suggest that zinc supplementation can ameliorate the effects of chronic stress on the growth, corporal weight, and immunocompetence of young mice.

Bacterial translocation and wasting in stressed mice.

The effects of stress on immunity and on the bacterial translocation from intestine to mesenteric lymph nodes, liver, and spleen were studied in a group of newborn CD1 mice. Animals were separated into three experimental groups. Mice from group I were stressed by intraperitoneal (i.p.) injections of heat-killed staphylococci for 4 weeks. Mice from group II were i.p. injected with saline solution only. The remaining mice, group III, were not injected. The clinical condition, presence of bacteria in abdominal organs, mitochondrial activity in splenic cells, lymphocyte proliferative response to Concanavalin-A and in vitro antibody production were evaluated in each mouse. Results showed that prolonged i.p. stressor challenge causes severe weight loss and immunodeficiency. The splenic lymphocytes from stressed mice exhibited a significant depression of both proliferative response to Concanavalin-A stimulation and anti-erythrocytes antibody synthesis. Instead, cultured in basal conditions, the splenic cells from stressed mice have an increased capacity to reduce the tetrazolium salts. Bacterial dissemination from intestine to mesenteric lymphoid nodes was also confirmed in the same group of mice. In contrast, mice in groups II and III presented no weight loss and no immunodeficiency. Results suggest that chronic biological stress induced in newborn mice could facilitate the translocation of Gram-negative bacteria. Probable pathogenic mechanisms are commented upon and a correlation is proposed between the bacterial dissemination and the wasting development.

Increment of enterobacterial common antigens in organ extracts from immunosuppressed mice.

This article describes the enterobacterial common antigen (ECA) content in the liver and spleen extracts from immunosuppressed two months old CFW mice which received a single dose (400 mg/kg body weight) of cyclophosphamide (CY). A complement fixation inhibition assay was used to measure the tissular concentration of ECA. The results showed that liver and spleen ethanol-soluble extracts from immunosuppressed mice had a greater quantity of ECA than those obtained from healthy mice (p < 0.001). Previous works have proven that ECA is a hapten shared by almost all Gram-negative bacteria, and CY is an alkylating agent useful to induce bacterial translocation. Therefore, the increments observed in tissular ECA concentration may indicate the extension of the enterobacterial dissemination from intestine to abdominal organs in CY-treated immunosuppressed mice.

[Selective IgA deficiency and malabsorption. Review of the literature apropos of a case]. / Deficiencia selectiva de IgA y malabsorción. Revisión de la literatura a propósito de un caso.

One of the most common primary immunodeficiencies is the selective deficiency of IgA, which is present in very variable clinical conditions. This situation had conducted to different criteria with respect to the clinical meaning in a particular patient. The association of immunodeficiency of IgA and intestinal malabsorption is reported as statistically significant in the international literature. Nevertheless, the precise pathogenic connection between them is unknown. The relationship between bowel and immune system is reviewed here, and illustrated with the clinical case of a six-year old girl who presented with malabsorption and selective deficiency of IgA.

Oral tolerance impairment in mice with staphylococci-induced wasting syndrome.

The effects of staphylococci-induced experimental wasting disease on the immune response of 1 month old CD1 mice were investigated. Animals were separated into different subgroups in order to study their cellular immune competence. Malnutrition of wasted mice was associated with anorexia, diarrhea and weakness. Footpad-injected splenic cells produced normal graft vs. host (GvH) reactions in the popliteal lymph nodes of F1 hybrids. In other experiments, the SRBC intragastric feeding of wasted mice did not cause a tolerant anti-erythrocyte humoral immune response. Three weeks after the staphylococci injections, convalescent erythrocyte-fed wasted mice exhibited an anti-SRBC PFC production similar to that observed in non-tolerant immunized control healthy mice. In return, healthy SRBC-fed control mice showed the specific attenuation of antibody response characteristics of oral tolerance. Differences were found between the immune competence of the undernourished staphylococci-treated wasted mice and those shown by other authors in protein-depleted mice.

Immune response to parasitic infection in mice without seminal vesicles.

A protracted depression of anti-parasitic antibody and DTH responses were observed in Balb/c mice after surgical extirpation of seminal vesicles and ulterior infection with Taenia crassiceps cysts. Inclusion of male seminal accessory glands into the network of immunogonadal interactions was proposed.

[Induction and recovery of immunologic weakening]. / Inducción y recuperación del desgaste inmunológico.

During this experimental work, we studied the immunological recuperation in CD1 mice in whom a weakening disease was induced using intraperitoneal injections of a sterile mixture of dead staphylococci. After a deep depression of the synthesis of anti-sheep red blood cell antibodies (SRBC) during the following 10 days after the induction of wasting, the animals regained their capability to produce anti-SRBC antibodies, significantly increasing. Two weeks after the injections were applied, the average number of antibody producing cells rose significantly and even doubled in the control group of healthy mice. Finally, after two weeks after this "rebound", the number of antibody forming cells return to normality. The article includes a discussion on the biological significance of this carried out in experimental animals while offering a hope for children with secondary immunological deficiencies or for those with repeatedly severe infections.

[Consequences of bacterial product interaction with the immune system in newborn mice]. / Consecuencias de la interacción de productos bacterianos con el sistema inmunológico de ratones recién nacidos.

The immunological competence of a newborn mice group, inoculated with a heat killed suspension of staphylococci, was studied to find out if the treated mice preserved the immunological competence of the T lymphocytes, for induce an allograft. A group of CD1 newborn male mice were injected intraperitoneally with the bacterial suspension, every three days during a four weeks period. Other group received only isotonic saline solution. The lymphocyte ability to form hemolytic plaques and their capacity to provoke a local graft-versus-host reaction in F1 receptor animals was studied in both groups. The results showed that the staphylococci treated newborn mice had a decreased capacity to form anti-erythrocyte antibodies without modification in their reactivity against histoincompatible antigens. Newborn mice, runting-like disease; bacterial inoculation; immunological response in.

[Enterobacterial antigen in human peripheral blood lymphocytes]. / Un antígeno de enterobacterias en los linfocitos de sangre periférica humana.

The following study has as prior history the research reports which have shown the existence of an antigenic tissue deposit in gram-negative enterobacteria. The antigens of the enterobacteria have also been found in the lymphocytic membranes and cytoplasm. Since intestinal lymphoid tissue cells can recirculate by means of the thoracic duct to the peripheral venous system, it was proposed that the circulating lymphocytes in healthy people could also contain small amounts of a common enterobacterial antigen. The study was carried out in 15 human venous blood samples, of which the lymphocytic population was separated to later be used in the preparation of 15 alcohol soluble extracts. This material was used for inhibiting the immuno-hemolysis assay in three occasions in order to show the presence of antigens shared by different enterobacterias, using as reference a fraction separated from the LPS of Escherichia coli 08. The results showed that the human lymphocytes also had antigenic determinants common to gram-negative bacteria.

[The association of HLA and disease]. / Asociación entre HLA y enfermedad.

The classification and genetic codification of human histocompatibility antigens (HLA), as well as the participation of these membrane structures in the stimulation mechanism of immune system and functional cell clones formation derived from T and B lymphocytes are reviewed in this work. In addition we present an up-date about the numerous association between HLA molecules expression and different human diseases described. The main mechanisms that have been proposed to explain the reasons for that associations are also presented; however we clarify that none of these can be consider as a proof of HLA participation in the etiopathogeny of those diseases. The HLA determination may help the physician to evaluate the risk of disease presentation and some of its complications as well as the prevention through the genetic advice.

Enterobacterial common antigen in the urine from children with cancer.

An inhibition of immunohemolysis assay was used to detect the enterobacterial common antigen (ECA) in urine samples from 40 children with cancer. Seven patients were excluded because bacterial contamination of urine. Thirty of the remaining 33 sterile samples gave an ECA-positive reaction. Specimens from 30 healthy control were negative. These findings may reflect a vascular dissemination and glomerular filtration of gram-negative lipopolysaccharide residues as a consequence of the malignancy. Detection of ECA in urine may be an useful tool for investigating the evolution of neoplastic diseases in the absence of urinary tract infections.

[Diminution of the primary antibody response in rats without seminal vesicles]. / Disminución de la respuesta primaria de anticuerpos en ratas sin vesículas seminales.

A group of 180 male Wistar rats was utilized to study the synthesis of antibodies against sheep red blood cells (SRBC) after the surgical extirpation of seminal vesicles at 8-10 days of age. Rats were randomly divided into three groups of 60 animals. Group 1 had the rats which seminal vesicles were removed surgically. The second group had the sham-operated controls which glands were exposed only and the incision was closed forthwith. Animals of group 3 were normal and nonoperated. Between 1-6 months of age the rats were immunized intraperitoneally with a SRBC suspension. Four days later the animals were sacrificed, the spleens were removed from the abdominal cavity and the lymphocyte suspensions were obtained after homogenization of the tissues. Adjusted splenic viable lymphocyte suspensions were mixed with SRBC and guinea pig serum to count the anti-erythrocyte hemolytic plaque forming cells, according to the modification of Cunningham of the previously described cell lytic assay of Jerne. The amounts of splenic lymphocytes synthesizing antibodies against SRBC in the rats without seminal vesicles were significantly lower (p less than 0.001) than that of the sham-operated animals, except at 30 days of age. Proportions of rats with a number of plaque forming cells (PFC) above the median value were significantly lower (p less than 0.001) in the group of rats without seminal vesicles. A X test was used to explore differences between the proportions observed in the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Amibiasis experimental. I.Caracteristicas de las lesiones despues de la inyeccion subcutanea de Entamoeba histolytica HK-9. / Experimental amebiasis. I. Characteristics of the lesions after subcutaneous injection of Entamoeba histolytica HK-9

Ratas Wistar adultas fueron inoculadas por via subcutanea con trofozoitos vivos de Entamoeba histolytica. Las caracteristicas microscopicas de las lesiones fueron diferentes de las que se han descrito en otros animales que han sido inyectados con amibas por otras vias y en diferentes tejidos En la piel de las ratas se encontro una intensa respuesta de fibroblastos que sintetizaron abundante colagena alrededor de la zona de necrosis central. Ademas el infiltrado pluricelular periferico contenia una gran cantidad de celulas cebadas. Se propone la amibiasis subcutanea de ratas como un modelo experimental que puede ser util para el estudio in vivo de las interacciones entre la colagena del huesped y las colagenasas de los trofozoitos. Asi mismo, se discute la posible actividad subcutanea experimental en ratas