RESUMEN
Anecdotal data in the past have suggested that the effect of the western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), on maize yield is greater under drought and the effect of drought is greater under rootworm infestations, but no field experiments have controlled both moisture and rootworm levels. Field studies were conducted in 2012, 2013, and 2014 with treatments in a factorial arrangement of western corn rootworm infestation levels, and maize hybrids (with and without tolerance to drought and rootworm feeding). The experiment was repeated under well-watered and drought conditions in adjacent plots. Leaf water potential and stomatal conductance data suggested significant plant stress was achieved in the drought plots toward the end of the season each year and maize hybrids only played a minor role. In particular, in 2012 and 2013 yield was dramatically lower for the drought experiment than for the well-watered experiment. However, the impacts of rootworm infestation level and maize hybrids on water potential, stomatal conductance, and yield were variable across years and between experiments. In fact, the only year that the main effect of rootworm infestation levels significantly impacted yield was in 2014, when an extremely high infestation level was added and this was only for the well-watered portion of the experiment. Overall, rootworm infestation level played a relatively minor role in maize productivity and it did not appear that soil moisture level influenced that to a large degree.
Asunto(s)
Antibiosis , Escarabajos/fisiología , Sequías , Herbivoria , Zea mays/fisiología , Animales , Escarabajos/crecimiento & desarrollo , Hibridación Genética , Larva/fisiología , Missouri , Distribución Aleatoria , Estrés Fisiológico , Zea mays/genéticaRESUMEN
Natural enemies need not consume herbivores to suppress herbivore populations. Behavioral interactions can adversely impact herbivore fitness from reduced time feeding, investment in defense, or injury from failed attacks. The importance of such "nonconsumptive effects" for herbivore suppression may vary across species based on the specificity and intensity of the herbivore defensive response. In a series of manipulative studies, we quantified the nature and consequences of nonconsumptive interactions between two parasitoid wasps, Aphidius ervi Haliday and Aphidius colemani Viereck, on two aphid species, pea aphids (Acyrthosiphon pisum (Harris)) and green peach aphids (Myzus persicae (Sulzer)). Both wasps successfully parasitize green peach aphids, but only A. ervi parasitizes pea aphids. We observed A. ervi antennating and stinging pea aphids and documented a decrease in pea aphid longevity in response to stinging even when the aphid survived the interaction and no mummy formed. The primary defensive tactic of pea aphids in response to either wasp species was dropping from the host plant. Both wasp species antennated and stung green peach aphids, but they elicited unique defensive behaviors. Green peach aphids kicked or emitted cornicle secretions in response to A. colemani but spent more time off the plant in the presence of A. ervi. Green peach aphid longevity and fecundity were not affected by wasp stings when the aphid survived and no mummy formed. Our study demonstrates the complexity of behavioral interactions between parasitoids and their potential hosts and contributes to a mechanistic understanding of variation in the nonconsumptive suppression of herbivore populations.
Asunto(s)
Áfidos/parasitología , Interacciones Huésped-Parásitos , Avispas/fisiología , Animales , Áfidos/genética , Aptitud Genética , OviposiciónRESUMEN
The western corn rootworm, Diabrotica virgifera virgifera LeConte, is the most important insect of maize, Zea mays L., but knowledge of its interaction with water deficit on maize production is lacking. A series of greenhouse experiments using three infestation levels of the western corn rootworm, D. virgifera virgifera, under well-watered, moderately dry, and very dry soil moisture levels were conducted to quantify the interaction of western corn rootworm and soil water deficit on B73×Mo17 maize growth and physiology. Three separate experiments were conducted. Soil moisture regimes were initiated 30 d postplanting for experiments using neonate and second-instar larvae and 30 d postinfestation in the experiment using eggs. In the neonate and second-instar experiments, there were no significant differences among western corn rootworm levels in their effects on leaf water potential, shoot dry weight, and root dry weight. The interaction of western corn rootworm and soil moisture significantly impacted the larval recovery in the neonate experiment, but no other significant interactions were documented between soil moisture levels and rootworm infestation levels. Overall, the results indicate that under the conditions of these experiments, the effect of water deficit was much greater on plants than the effect of western corn rootworm and that the interactions between water deficit and western corn rootworm levels minimally affected the measured parameters of plant performance.
Asunto(s)
Escarabajos/fisiología , Sequías , Agua/fisiología , Zea mays/crecimiento & desarrollo , Animales , Larva/fisiología , Raíces de Plantas/crecimiento & desarrollo , Brotes de la Planta/crecimiento & desarrollo , Estomas de Plantas/fisiologíaRESUMEN
Current therapies to treat inflammatory bowel diseases have limited efficacy, significant side effects, and often wane over time. Little is known about the cellular and molecular mechanisms operative in the process of mucosal healing from colitis. To study such events, we developed a new model of reversible colitis in which adoptive transfer of CD4(+)CD45RB(hi) T cells into Helicobacter typhlonius-colonized lymphopenic mice resulted in a rapid onset of colonic inflammation that was reversible through depletion of colitogenic T cells. Remission was associated with an improved clinical and histopathological score, reduced immune cell infiltration to the intestinal mucosa, altered intestinal gene expression profiles, regeneration of the colonic mucus layer, and the restoration of epithelial barrier integrity. Notably, colitogenic T cells were not only critical for induction of colitis but also for maintenance of disease. Depletion of colitogenic T cells resulted in a rapid drop in tumor necrosis factor α (TNFα) levels associated with reduced infiltration of inflammatory immune cells to sites of inflammation. Although neutralization of TNFα prevented the onset of colitis, anti-TNFα treatment of mice with established disease failed to resolve colonic inflammation. Collectively, this new model of reversible colitis provides an important research tool to study the dynamics of mucosal healing in chronic intestinal remitting-relapsing disorders.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Colitis/inmunología , Infecciones por Helicobacter/inmunología , Enfermedades Inflamatorias del Intestino/inmunología , Mucosa Intestinal/fisiología , Traslado Adoptivo , Animales , Linfocitos T CD4-Positivos/trasplante , Movimiento Celular , Células Cultivadas , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Humanos , Mucosa Intestinal/patología , Depleción Linfocítica , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Factor de Necrosis Tumoral alfa/metabolismo , Cicatrización de HeridasRESUMEN
Deficiencies in early complement components are associated with the development of systemic lupus erythematosus (SLE) and therefore early complement components have been proposed to influence B lymphocyte activation and tolerance induction. A defect in apoptosis is a potential mechanism for breaking of peripheral B cell tolerance, and we hypothesized that the lack of the early complement component C4 could initiate autoimmunity through a defect in peripheral B lymphocyte apoptosis. Previous studies have shown that injection of a high dose of soluble antigen, during an established primary immune response, induces massive apoptotic death in germinal centre B cells. Here, we tested if the antigen-induced apoptosis within germinal centres is influenced by early complement components by comparing complement C4-deficient mice with C57BL/6 wild-type mice. We demonstrate that after the application of a high dose of soluble antigen in wild-type mice, antibody levels declined temporarily but were restored almost completely after a week. However, after antigen-induced apoptosis, B cell memory was severely limited. Interestingly, no difference was observed between wild-type and complement C4-deficient animals in the number of apoptotic cells, restoration of antibody levels and memory response.
Asunto(s)
Apoptosis/inmunología , Linfocitos B/inmunología , Complemento C4/deficiencia , Complemento C4/inmunología , Lupus Eritematoso Sistémico/inmunología , Animales , Antígenos/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Centro Germinal/inmunología , Tolerancia Inmunológica , Memoria Inmunológica , Ratones , Ratones Endogámicos C57BL , Nitrofenoles/inmunología , FenilacetatosRESUMEN
During evolution, the development of secondary lymphoid organs has evolved as a strategy to promote adaptive immune responses at sites of antigen sequestration. Mesenteric lymph nodes (LNs) and Peyer's patches (PPs) are localized in proximity to mucosal surfaces, and their development is coordinated by a series of temporally and spatially regulated molecular events involving the collaboration between hematopoietic, mesenchymal, and, for PPs, epithelial cells. Transcriptional control of cellular differentiation, production of cytokines as well as adhesion molecules are mandatory for organogenesis, recruitment of mature leukocytes, and lymphoid tissue organization. Similar to fetal and neonatal organogenesis, lymphoid tissue neoformation can occur in adult individuals at sites of chronic stimulation via cytokines and TNF-family member molecules. These molecules represent new therapeutic targets to manipulate the microenvironment during autoimmune diseases.
Asunto(s)
Inmunidad Mucosa/genética , Ganglios Linfáticos/inmunología , Organogénesis/inmunología , Ganglios Linfáticos Agregados/inmunología , Animales , Evolución Biológica , Humanos , Inmunidad Mucosa/inmunología , Ganglios Linfáticos/embriología , Ganglios Linfáticos/crecimiento & desarrollo , Organogénesis/genética , Ganglios Linfáticos Agregados/embriología , Ganglios Linfáticos Agregados/crecimiento & desarrolloRESUMEN
Mouse mammary tumor virus (MMTV) infects the host via mucosal surfaces and exploits the host immune system for systemic spread and chronic infection. We have tested a neutralizing rat monoclonal antibody specific for the retroviral envelope glycoprotein gp52 for its efficiency in preventing acute and chronic mucosal and systemic infection. The antibody completely inhibits the superantigen response and chronic viral infection following systemic or nasal infection. Surprisingly however, the antibody only partially inhibits the early infection of antigen-presenting cells in the draining lymph node. Despite this initially inefficient protection from infection, superantigen-specific B- and T-cell responses and systemic viral spread are abolished, leading to complete clearance of the retroviral infection and hence interruption of the viral life cycle. In conclusion, systemic neutralizing monoclonal antibodies can provide an efficient protection against chronic retroviral amplification and persistence.
Asunto(s)
Virus del Tumor Mamario del Ratón/crecimiento & desarrollo , Virus del Tumor Mamario del Ratón/inmunología , Animales , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Antivirales/administración & dosificación , Antígenos Virales de Tumores/genética , Antígenos Virales de Tumores/inmunología , Linfocitos B/inmunología , Linfocitos B/patología , Secuencia de Bases , Diferenciación Celular , ADN Viral/genética , Femenino , Inmunidad Mucosa , Inmunización Pasiva , Neoplasias Mamarias Experimentales/inmunología , Neoplasias Mamarias Experimentales/prevención & control , Virus del Tumor Mamario del Ratón/genética , Ratones , Ratones Endogámicos BALB C , Pruebas de Neutralización , Ratas , Ratas Endogámicas Lew , Infecciones por Retroviridae/inmunología , Infecciones por Retroviridae/prevención & control , Infecciones Tumorales por Virus/inmunología , Infecciones Tumorales por Virus/prevención & controlRESUMEN
MVA is a candidate vector for vaccination against pathogens and tumors. Little is known about its behaviour in mucosal tissues. We have investigated the fate and biosafety of MVA, when inoculated by different routes in C57BL/6 mice. Intranasal inoculation targeted the virus to the nasal associated lymphoid tissue and the lungs, whereas systemic inoculation led to distribution of MVA in almost all lymphoid organs, lungs and ovaries. Intravaginal, intrarectal and intragastric inoculations failed to induce efficient infection. After 48 h no virus was detectable any more in the organs analyzed. Upon intranasal inoculation, no inflammatory reactions were detected in the central nervous system as well as the upper and lower airways. These results show the tropism of MVA and indicate that high doses of recombinant MVA are safe when nasally administered, a vaccination route known to elicit strong cellular and humoral immune responses in the female genital tract.
Asunto(s)
Sistema Digestivo/virología , Genitales Femeninos/virología , Ganglios Linfáticos/virología , Membrana Mucosa/virología , Sistema Respiratorio/virología , Vacunas/administración & dosificación , Vacunas/clasificación , Virus Vaccinia/clasificación , Virus Vaccinia/aislamiento & purificación , Administración Intranasal , Animales , Encéfalo/virología , Femenino , Inmunidad Mucosa/inmunología , Pulmón/virología , Ratones , Ratones Endogámicos C57BL , Vacunas/efectos adversos , Vacunas/inmunología , Virus Vaccinia/inmunologíaRESUMEN
CD4+CD3- cells are the predominant hematopoietic cells found in mouse fetal intestine. We prove their role as Peyer's patch (PP)-inducing cells by transfer into neonatal PP-deficient mice. To test the requirement of chemokines and adhesion molecules in induction of PP, we studied mice deficient in CXCR5 and/or alpha4beta1 integrin-mediated adhesion. CXCR5-/- mice have CD4+CD3- cells, which are inefficient in inducing PP formation. We show here that CXCR5/CXCL13 signaling activates alpha4beta1 integrin on CD4+CD3- cells. Blocking of beta1 integrin or VCAM-1, the ligand of alpha4beta1 integrin, inhibits PP formation. This study demonstrates the link between chemokine receptors and adhesion molecules that regulates stromal/hematopoietic cell interaction leading to PP formation.
Asunto(s)
Linfocitos T CD4-Positivos/fisiología , Integrina alfa4beta1/fisiología , Ganglios Linfáticos Agregados/crecimiento & desarrollo , Receptores de Citocinas/fisiología , Traslado Adoptivo , Animales , Complejo CD3/análisis , Linfocitos T CD4-Positivos/trasplante , Adhesión Celular , Quimiocina CXCL13 , Quimiocinas CXC/fisiología , Síndromes de Inmunodeficiencia/genética , Síndromes de Inmunodeficiencia/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Inmunológicos , Morfogénesis , Quimera por Radiación , Receptores CXCR5 , Receptores de Quimiocina , Receptores de Citocinas/deficiencia , Receptores de Citocinas/genética , Transducción de Señal/inmunología , Células del Estroma/citología , Molécula 1 de Adhesión Celular Vascular/fisiologíaRESUMEN
B cells undergo a complex series of maturation and selection steps in the bone marrow and spleen during differentiation into mature immune effector cells. The tumor necrosis factor (TNF) family member B cell activating factor of the TNF family (BAFF) (BLyS/TALL-1) plays an important role in B cell homeostasis. BAFF and its close homologue a proliferation-inducing ligand (APRIL) have both been shown to interact with at least two receptors, B cell maturation antigen (BCMA) and transmembrane activator and cyclophilin ligand interactor (TACI), however their relative contribution in transducing BAFF signals in vivo remains unclear. To functionally inactivate both BAFF and APRIL, mice transgenic for a soluble form of TACI were generated. They display a developmental block of B cell maturation in the periphery, leading to a severe depletion of marginal zone and follicular B2 B cells, but not of peritoneal B1 B cells. In contrast, mice transgenic for a soluble form of BCMA, which binds APRIL, have no detectable B cell phenotype. This demonstrates a crucial role for BAFF in B cell maturation and strongly suggests that it signals via a BCMA-independent pathway and in an APRIL-dispensable way.
Asunto(s)
Linfocitos B/citología , Proteínas de la Membrana/metabolismo , Receptores del Factor de Necrosis Tumoral/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Factor Activador de Células B , Antígeno de Maduración de Linfocitos B , Linfocitos B/fisiología , Diferenciación Celular , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Ratones Transgénicos , Receptores del Factor de Necrosis Tumoral/genética , Proteína Activadora Transmembrana y Interactiva del CAML , Miembro 13 de la Superfamilia de Ligandos de Factores de Necrosis TumoralRESUMEN
Formation of Peyer's patches requires complex interactions between the gut epithelium, the mesenchyme, and bone-marrow-derived hematopoietic progenitors. The first Peyer's patches anlage appear around embryonic day 15.5, when the endoderm has undergone transition to a simple epithelium, the lymphatic vessels have reached the intestinal mucosa, and mesenchymal cells have started to form clusters. Recent data using knockout mice provide insight into the molecular nature of the signals that mediate Peyer's patch ontogeny. These include members of the tumor-necrosis factor family and homeostatic chemokines.
Asunto(s)
Desarrollo Embrionario y Fetal , Ganglios Linfáticos Agregados/embriología , Ganglios Linfáticos Agregados/metabolismo , Animales , Células Sanguíneas/metabolismo , Diferenciación Celular , Quimiocinas/metabolismo , Epitelio/metabolismo , Regulación del Desarrollo de la Expresión Génica , Genes Homeobox/genética , Humanos , Mucosa Intestinal/metabolismo , Intestinos/irrigación sanguínea , Intestinos/citología , Intestinos/embriología , Mesodermo/metabolismo , Ganglios Linfáticos Agregados/irrigación sanguínea , Ganglios Linfáticos Agregados/citología , Transducción de Señal , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Our study describes tissue-specific migration of T and B cells during a localized anti-viral immune response. After mouse mammary tumor virus (MMTV) injection, B lymphocytes of the draining lymph node become infected and present a retroviral superantigen to CD4(+) T lymphocytes. Infected B cells receive superantigen-mediated help in a fashion comparable to classical immune responses. To investigate the fate of T and B lymphocytes that had interacted via cognate help in the same peripheral lymph node microenvironment we adoptively transferred them into naive recipients. Here we show that MMTV-infected B cells and superantigen-stimulated T cells were programmed to migrate to distinct sites of the body. Plasmablasts but not T cells migrated to the mammary gland and activated alpha4beta1 integrins were found to have a crucial role in the migration to the mammary gland. In contrast, T cells had a much higher affinity for secondary lymphoid organs and large intestine. This demonstrates that upon antigen-driven B and T lymphocyte interaction in the local draining lymph node a subset-specific homing program for B and T lymphocytes is induced.
Asunto(s)
Linfocitos B/inmunología , Mama/inmunología , Linfocitos T CD4-Positivos/inmunología , Movimiento Celular , Tejido Linfoide/inmunología , Traslado Adoptivo , Animales , Antígenos Virales/inmunología , Linfocitos B/trasplante , Linfocitos T CD4-Positivos/trasplante , Femenino , Integrina alfa4beta1 , Integrinas/fisiología , Activación de Linfocitos , Virus del Tumor Mamario del Ratón/inmunología , Ratones , Ratones Endogámicos BALB C , Receptores Mensajeros de Linfocitos/fisiología , Infecciones por Retroviridae/inmunología , Superantígenos/inmunología , Molécula 1 de Adhesión Celular Vascular/metabolismoRESUMEN
B cells can either differentiate in germinal centers or in extrafollicular compartments of secondary lymphoid organs. Here we show the migration properties of B cells after differentiation in murine peripheral lymph node infected with mouse mammary tumor virus. Naive B cells become activated, infected, and carry integrated retroviral DNA sequences. After production of a retroviral superantigen, the infected B cells receive cognate T cell help and differentiate along the two main differentiation pathways analogous to classical Ag responses. The extrafollicular differentiation peaks on day 6 of mouse mammary tumor virus infection, and the follicular one becomes detectable after day 10. B cells participating in this immune response carry a retroviral DNA marker that can be detected by using semiquantitative PCR. We determined the migration patterns of B cells having taken part in the T cell-B cell interaction from the draining lymph node to different tissues. Waves of immigration and retention of infected cells in secondary lymphoid organs, mammary gland, salivary gland, skin, lung, and liver were observed correlating with the two peaks of B cell differentiation in the draining lymph node. Other organs revealed immigration of infected cells at later time points. The migration properties were correlated with a strong up-regulation of alpha(4)beta(1) integrin expression. These results show the migration properties of B cells during an immune response and demonstrate that a large proportion of extrafolliculary differentiating plasmablasts can escape local cell death and carry the retroviral infection to peripheral organs.
Asunto(s)
Subgrupos de Linfocitos B/inmunología , Ganglios Linfáticos/inmunología , Neoplasias Mamarias Experimentales/inmunología , Virus del Tumor Mamario del Ratón/inmunología , Células Plasmáticas/inmunología , Infecciones por Retroviridae/inmunología , Infecciones Tumorales por Virus/inmunología , Animales , Antígenos CD/biosíntesis , Subgrupos de Linfocitos B/metabolismo , Subgrupos de Linfocitos B/patología , Subgrupos de Linfocitos B/virología , Diferenciación Celular/inmunología , Movimiento Celular/inmunología , Femenino , Miembro Posterior , Integrina alfa4 , Integrina alfa4beta1 , Integrina beta1/biosíntesis , Integrinas/biosíntesis , Ganglios Linfáticos/patología , Ganglios Linfáticos/virología , Activación de Linfocitos , Tejido Linfoide/inmunología , Tejido Linfoide/patología , Tejido Linfoide/virología , Neoplasias Mamarias Experimentales/patología , Neoplasias Mamarias Experimentales/virología , Ratones , Ratones Endogámicos BALB C , Células Plasmáticas/metabolismo , Células Plasmáticas/patología , Células Plasmáticas/virología , Receptores Mensajeros de Linfocitos/biosíntesis , Infecciones por Retroviridae/patología , Infecciones Tumorales por Virus/patologíaRESUMEN
During T cell-dependent antibody responses lymph node B cells differentiate either to plasmablasts that grow in the medullary cords, or to blasts that proliferate in follicles forming germinal centers. Many plasmablasts differentiate to plasma cells locally, but some leave the medullary cords and migrate to downstream lymph nodes. To assess the basis for this migration, changes in the responsiveness of B cells to a range of chemokines have been studied as they differentiate. Naive B cells express high levels of CCR6, CCR7, CXCR4 and CXCR5. When activated B cells grow in follicles the expression of these chemokine receptors and the responsiveness to the respective chemokines is retained. During the extrafollicular response, plasmablast expression of CXCR5 and responsiveness to B-lymphocyte chemoattractant (CXCR5) as well as to secondary lymphoid tissue chemokine (CCR7) and stromal cell-derived factor (SDF)-1 (CXCR4) are lost while a weak response towards the CCR6 chemokine LARC is maintained. Despite losing responsiveness to SDF-1, extrafollicular plasmablasts still express high levels of CXCR4 on the cell surface. These results suggest that the combined loss of chemokine receptor expression and of chemokine responsiveness may be a necessary prerequisite for cells to migrate to the medullary cords and subsequently enter the efferent lymph.
Asunto(s)
Linfocitos B/fisiología , Quimiocinas/fisiología , Células Madre Hematopoyéticas/fisiología , Ganglios Linfáticos/citología , Células Plasmáticas/fisiología , Animales , Diferenciación Celular , Movimiento Celular , Pollos , Femenino , Virus del Tumor Mamario del Ratón/inmunología , Ratones , Ratones Endogámicos BALB C , Receptores de Quimiocina/análisis , Receptores de Quimiocina/fisiología , gammaglobulinas/inmunologíaRESUMEN
Nephrolithiasis is a common disease of multifactorial ethiopatogenesis. The majority of stone formers has disturbances in the metabolism and excretion of stone constituents, promotors or inhibitors of crystallization. The aim of our study was to evaluate metabolic disturbances in children with nephrolithiasis in the early stages of the disease. Cases with severe urinary obstruction, infection and glomerular filtration decrease were excluded. Daily calcium, uric acid, oxalate, phosphate, sodium, potassium, chloride, citrate, and magnesium excretion was examined in 27 children (12 M, 15 F, mean age--10.4 +/- 3.9 y). Hypercalciuria (10 cases) and hiperurykosuria (8 cases) were most often found in the studied group. We concluded that early diagnosis of metabolic background of stone formation (promotors and inhibitors) enables to apply proper preventive measures.
Asunto(s)
Calcio/orina , Enfermedades Metabólicas/complicaciones , Ácido Úrico/orina , Cálculos Urinarios/complicaciones , Niño , Preescolar , Femenino , Humanos , MasculinoRESUMEN
UNLABELLED: The objective of this study was to assess concentrations of selected markers of coagulation in children with relapse of idiopathic nephrotic syndrome during a 6-week therapy. Study groups: 22 subjects (32 relapses)--14 males, 8 females (mean age 7.15 +/- 1.5 y.) with no thrombotic complications were included into the study. All children were clinically steroid-sensitive. METHODS: Coagulation markers (platelet count, thrombin time, APTT, INR, fibrinogen 1 + 2 fragments (F1 + 2), thrombin-antithrombin complexes (TAT), serum levels of D-dimer (DD), fibrin monomers (FM) and antithrombin activity (ATIII)) were measured three times: on admission, after 2 and 6 weeks. The control group consisted of 13 healthy children. RESULTS: Serum concentration of TAT or F1 + 2 did not differ between 3 stages (p > 0.05). However, values at 0 and 2 weeks were significantly higher than in control group (p < 0.05). We found no correlation between TAT or F1 + 2 and FBG, ALB, TCH, TG levels. [table: see text] CONCLUSIONS: The coagulation cascade in relapse of NS was activated during first 6 weeks of therapy whereas metabolic disturbances (low ALB, high FGB, TCH, TG, high platelets) normalized. It is speculative whether it was caused by active immunological process but definitely it resulted in "prothrombotic state" in INS patients.
Asunto(s)
Factores de Coagulación Sanguínea/metabolismo , Síndrome Nefrótico/metabolismo , Adolescente , Biomarcadores , Niño , Preescolar , Femenino , Fibrinógeno/metabolismo , Humanos , Masculino , RecurrenciaRESUMEN
Continuous ambulatory peritoneal dialysis (CAPD) is a renal replacement therapy of choice in small children, the elderly, diabetics, subjects with cardiovascular disease and with difficulties in vascular access. Frequent complication of this method is the infection of the Tenckhoff catheter exit site, definition of which has not been firmly established yet. The aim of this study was to assess the frequency of catheter exit infections, its bacterial etiology and the efficacy of antibiotic treatment. The study material consisted of 21 subjects (11 female, 10 male) treated with CAPD in 1992-99 at our department, mean age 19.8 +/- 11.8 yrs, with mean CAPD treatment time 33 +/- 27 months. They were divided into two groups: group I--patients aged > or = 5 yrs, and group II--patients aged 15 yrs. Mean catheter usage time was 15.8 +/- 14.9 months. 43 cases of catheter exit site infection was diagnosed (0.7 case of infection per patient per year). Infection frequency was found to be 1 case in 9.4 months and 1 in 26.5 months, in group I and II, respectively (p < 0.001). Catheter usage in two groups was 10.4 +/- 8.2 and 21.4 +/- 15.4 months, respectively (p < 0.01). The most frequent pathogen was S. aureus (31 cases), with 5 cases of MRSA strains found. Antibiotic treatment was applied according to Keane's recommendations and it lasted 13.2% of CAPD treatment duration. In conclusion, catheter exit site infection occurred more often in children under the age of 5 yrs, and the catheter usage time was significantly shorter in this group of patients.
Asunto(s)
Fallo Renal Crónico/terapia , Diálisis Peritoneal Ambulatoria Continua/métodos , Infecciones Relacionadas con Prótesis/epidemiología , Infecciones Relacionadas con Prótesis/microbiología , Adolescente , Adulto , Antibacterianos/uso terapéutico , Niño , Preescolar , Femenino , Humanos , Incidencia , Lactante , Masculino , Infecciones Relacionadas con Prótesis/tratamiento farmacológicoRESUMEN
Mouse mammary tumor virus has developed strategies to exploit the immune response. It requires vigorous immune stimulation to achieve efficient infection. The infected antigen-presenting cells present a viral superantigen on the cell surface which stimulates strong CD4-mediated T-cell help but CD8 T-cell responses are undetectable. Despite the high frequency of superantigen-reactive T cells, the superantigen-induced immune response is comparable to classical antigen responses in terms of T-cell priming, T-cell-B-cell collaboration as well as follicular and extra-follicular B-cell differentiation. Induction of systemic anergy is observed, similar to classical antigen responses where antigen is administered systemically but does not influence the role of the superantigen-reactive T cells in the maintenance of the chronic germinal center reaction. So far we have been unable to detect a cytotoxic T-cell response to mouse mammary tumor virus peptide antigens or to the superantigen. This might yet represent another step in the viral infection strategy.
Asunto(s)
Formación de Anticuerpos , Inmunidad Celular , Virus del Tumor Mamario del Ratón/inmunología , Infecciones por Retroviridae/inmunología , Infecciones Tumorales por Virus/inmunología , Secuencia de Aminoácidos , Animales , Células Presentadoras de Antígenos/inmunología , Antígenos Virales/inmunología , Humanos , Ratones , Datos de Secuencia Molecular , Superantígenos/inmunología , Linfocitos T/inmunología , Linfocitos T Citotóxicos/inmunología , Virosis/inmunologíaRESUMEN
The neonatal immune response is impaired during the first weeks after birth. To obtain a better understanding of this immaturity, we investigated the development of T cell interactions with B cells in mice. For this purpose, we analyzed the immune response to three T-dependent antigens in vivo: (i) the polyclonal antibody response induced by vaccinia virus; (ii) the production of polyclonal and specific antibodies following immunization with hapten-carrier conjugates; (iii) the mouse mammary tumor virus superantigen (sAg) response involving an increase in sAg-reactive T cells and induction of polyclonal antibody production. After vaccinia virus injection into neonates, the polyclonal antibody response was similar to that observed in adult mice. The antibody response to hapten-carrier conjugates, however, was delayed and reduced. Injection with sAg-expressing B cells from neonatal or adult mice allowed us to determine whether B cells, T cells or both were implicated in the reduced immune response. In these sAg responses, neonatal T cells were stimulated by both neonatal and adult sAg-presenting B cells but only B cells from adult mice differentiated into IgM- and IgG-secreting plasma cells in the neonatal environment in vivo. Injecting neonatal B cells into adult mice did not induce antibody production. These results demonstrate that the environment of the neonatal lymph node is able to support a T and B cell response, and that immaturity of B cells plays a key role in the reduced immune response observed in the neonate.