Role of CD8+ T cells in endogenous interleukin-10 secretion associated with visceral leishmaniasis

This study examined the role and source of endogenous interleukin-10 (IL) secretion in visceral leishmaniasis (VL). The amounts of endogenous and Leishmania specific IL-10 and interferon-gamma (IFN) secreted by peripheral blood mononuclear cells (PBMC) from VL patients were compared. The correlation coefficient between endogenous IL-10 secretion and Leishmania specific IFN-gamma was -0. 77, suggesting a major role for endogenous IL-10 secretion in VL. The effects of CD4+ and CD8+ T cell clones, isolated from a treated VL patient, on IL-10 secretion were assayed by mixing the clones with autologous, inactivated PBMC. The CD8+ clones mediated increased levels of IL-10 secretion in the presence of PBMC alone suggesting that CD8+ T cells may mediate endogenous IL-10 secretion.

Role of CD8+ T cells in endogenous interleukin-10 secretion associated with visceral leishmaniasis.

This study examined the role and source of endogenous interleukin-10 (IL) secretion in visceral leishmaniasis (VL). The amounts of endogenous and Leishmania specific IL-10 and interferon-gamma (IFN) secreted by peripheral blood mononuclear cells (PBMC) from VL patients were compared. The correlation coefficient between endogenous IL-10 secretion and Leishmania specific IFN-gamma was -0. 77, suggesting a major role for endogenous IL-10 secretion in VL. The effects of CD4+ and CD8+ T cell clones, isolated from a treated VL patient, on IL-10 secretion were assayed by mixing the clones with autologous, inactivated PBMC. The CD8+ clones mediated increased levels of IL-10 secretion in the presence of PBMC alone suggesting that CD8+ T cells may mediate endogenous IL-10 secretion.

Parenting stress and mothers of young children with chronic illness: a cross-cultural study.

This study examined the sources of parenting stress among mothers from Israel, Japan, Jordan, and the United States who had a young child with a chronic illness. The results indicated mothers from all four countries experienced high levels of child-focused and parent-focused stress that indicated a need for nursing intervention.

Immunotherapy for visceral leishmaniasis: ability of factors produced during anti-leishmania responses of skin test positive adults to inhibit peripheral blood mononuclear cell activities associated with visceral leishmaniasis.

The course of human Leishmania chagasi infections appears to be determined by the balance between type 1 (Tl) CD4+ and CD8+ T suppressor (Ts) cell activities. Skin test positive adults living in hyperendemic areas who have no history of visceral leishmaniasis (VL) have Tl CD4+ T cell immunodominant responses against L. chagasi. The cytokines they secrete during anti-leishmania responses are a probable source of cytokines which inhibit the CD8+ Ts cells associated with VL. The ability of supernatants generated from peripheral blood mononuclear cells derived from skin test positive adults to reverse immune responses which appear to be mediated by CD8+ Ts cells was assessed in three sets of screening assays. The supernatants displayed three candidate factors. One, which could be explained by Leishmania antigens in the supernatant, decreased high endogenous IL-10 secretion characteristic of one class of VL patients. A second activity decreased high endogenous proliferation characteristic of the same class of patients without decreasing antigen specific proliferation. The third activity inhibited or killed CD8+ T cells but not CD4+ T cells. These activities might be useful in treating VL.

Diaper type and fecal contamination in child day care.

In this study, modern all-in-one, front closure, reusable cloth diapers were compared with single-use, disposable paper diapers for their effect on fecal contamination in the child day care environment. Four licensed child day care centers were surveyed from which 1722 bacterial samples were cultured. The frequency of isolation of fecal organisms ranged from a low of 12% of the total bacterial isolates at a center using cloth diapers to a high of 46% and 45%, respectively, obtained at a center using first paper and then cloth diapers. Diaper type, cloth versus paper, when the method of application and the handling are made comparable, showed no significant difference in the frequency or the intensity of fecal contamination in child day care centers, as measured in the play/sleep area, the diaper change area, or on the hands of the care givers and children. Future studies to control microbial contamination in child day care centers should focus on effective ways of reducing contamination of sink faucets, hands of the caregivers, and hands of the children.

Fecal contamination in child day care centers: cloth vs paper diapers.

OBJECTIVES: Cloth diapers with front closure and all-in-one design were compared with paper diapers containing absorbent gel material for their influence on fecal contamination of the environment in licensed child day care centers. METHODS: One infant room and two toddler rooms in each of four day care centers were monitored for the presence of fecal bacteria. Microbial samples were taken from the play/sleep area, the diaper-changing area, and the hands of the caregivers and the children. Sampling was done twice weekly for two 4-week periods. Each center used either cloth or paper diapers during the first period, changing to the other diaper type during the second period. RESULTS: A total of 1722 samples were cultured, 881 during the first 4 weeks and 841 during the second 4 weeks. The frequency of isolation of fecal organisms ranged from a low of 12% of the total bacteria isolates at a center using cloth diapers, to highs of 46% and 45%, respectively, at a center using first paper and then cloth diapers. Sink faucets and the hands of the caregivers and the children were often contaminated. CONCLUSIONS: Analysis of the results of comparisons between cloth and paper diapers showed no significant difference in the frequency (F = .380, P < .535) or the intensity of fecal contamination in child day care centers.

The experiences of discrimination: challenges for chronically ill children.

The purpose of this study was to examine mothers' perceptions of discrimination experienced by chronically ill school-age children. Discrimination was seen to originate within the school system, peer group, and community and governing institutions. Several demographic and child factors were found to significantly predict mothers' perceptions of discrimination. Nursing implications addressing discrimination for chronically ill children and families are addressed.

Vygotsky's Zone of Proximal Development: implications for nurse assistance of children's learning.

Vygotsky's general theoretical framework of cognitive development is reviewed, including his concept of the zone of proximal development: the region of potential mastery lying between the level at which the child has the ability for independent performance and the level at which the child can master the task only with adult collaboration. Examples of the use of Vygotskian theory in nursing practice are provided.

Potential role for interleukin-10 in the immunosuppression associated with kala azar.

Patients with acute kala azar are generally nonreactive in a number of immunologic assays, including T cell proliferation and generation of macrophage-activating cytokines, principally IFN-gamma, in response to leishmania antigens in vitro. To test for potential immunosuppressive factors, a series of T cell lines and clones were established from patients with acute kala azar, from patients after chemotherapy for kala azar, and from skin test-positive adults from the same endemic region. Although CD4+ T cell lines and clones could be readily established from the skin test-positive adults, lines and clones from acute or treated patients were heavily biased in expression of CD8+. The CD8+ cells from acute patients did not themselves release cytokines in response to leishmania antigens in vitro, but markedly affected the cytokine profile of peripheral blood mononuclear cells isolated 1 yr later after recovery. Addition of the CD8+ cells caused inhibition of lymphoproliferation and IFN-gamma release, with augmentation of IL-6 and IL-10 release. The inhibitory effects of the CD8+ cells could be partially abrogated by antibodies to IL-10 but not by antibodies to IL-4. Analysis of four patients with acute kala azar demonstrated release of IL-10 that could not be demonstrated in supernatants from asymptomatic skin test-positive individuals. Generation of IL-10 may contribute to the profound suppression of IFN-gamma release that occurs during kala azar due to Leishmania chagasi.

Chronically ill children in self-care: issues for pediatric nurses.

The self-care (or latchkey) arrangement for children with a chronic illness is an important topic for pediatric nurses. This article reviews the impact of self-care for children's development, examines the effectiveness of teaching self-care skills to latchkey children, and provides assessment and intervention information to help pediatric nurses who are working with parents and children with chronic illness who are in self-care.

Correlates of Leishmania-specific immunity in the clinical spectrum of infection with Leishmania chagasi.

Patients from across the spectrum of clinical manifestations of Leishmania chagasi infection were evaluated for in vitro correlates of immunity. Peripheral blood mononuclear cells were assayed for parasite-specific lymphoproliferation, cytokine generation, and the capacity to activate autologous macrophages to kill intracellular amastigotes. Patients with acute kala-azar were generally unreactive in each of these assays. Children with subclinical infection demonstrated relatively low levels of proliferation and interferon-gamma production, but none went on to develop overt kala-azar during the study. Patients evaluated after therapy for kala-azar demonstrated yet higher levels of lymphoproliferation and cytokine generation and produced low but significant levels of cytokines in vitro in response to parasite antigens, but not during the activation of infected macrophages. Finally, peripheral blood mononuclear cells from adults with positive delayed-type hypersensitivity responses and no history of kala-azar showed the broadest reactivity in vitro. These patients' cells generated the largest amounts of activating cytokines in vitro during the activation of autologous macrophages to a leishmanicidal state.

Sampling rare pediatric populations.

The sampling of general populations of individuals or households for survey research is well described. However, much of the focus of pediatric nursing research is on special or rare populations. This article presents techniques that may be used to locate rare populations for pediatric nursing research. Additionally, development and analysis of one technique used to locate a sample frame for a survey of time use of chronically ill school-age children is discussed.

Reconstitution of Leishmania immunity in severe combined immunodeficient mice using Th1- and Th2-like cell lines.

Leishmania major disseminates in genetically susceptible BALB/c mice to cause fatal disease. Progressive infection has been linked to the failure of parasite-specific Th1, IFN-gamma-producing, CD4+ T lymphocytes to expand and direct macrophage activation and control of intracellular parasitism. In contrast, Th2 CD4+ cell expansion accompanies disease progression. Immunomodulation using CD4 cell depletion at the time of infection results in control of infection and Th1 CD4+ cell expansion. A Th1-like cell line, H1A, was established from the draining lymph nodes of an anti-CD4-pretreated BALB/c mouse infected with L. major, H1A was CD4, TCR(+)-alpha/beta, and released IL-2 and IFN-gamma in response to parasite Ag. A Th2-like cell line, U1A, was established from the lymph node cells of an infected BALB/c mouse that was also CD4, TCR(+)-alpha/beta but released IL-4 and IL-5 after stimulation. Mice with severe combined immunodeficiency were reconstituted with H1A and U1A before infection with L. major. Non-reconstituted mice were unable to restrict parasite growth. Mice reconstituted with H1A healed infection, whereas mice reconstituted with U1A suffered exacerbation of disease. Analysis of spleen cells by flow cytometry confirmed the reconstitution of CD4+ cells in both instances, and stimulation with mitogen established that the lymphokine profile of the donor cells had been maintained during 6 to 8 wk of infection. Histologic analysis of the lesions confirmed migration of donated cells to sites of infection. Neutralization of IFN-gamma in H1A-reconstituted mice and IL-4 in U1A-reconstituted mice reversed the disease phenotype mediated by the two cell lines. These data demonstrate the capacity of CD4+ T cells alone to modulate both positively and negatively the course of leishmaniasis in a lymphokine-dependent manner.

Stability of school-age children's survey responses.

School-age children may have low levels of response stability on many questions asked in survey research. This article incorporates evidence from a three-wave panel study into a discussion of some possible causes of low stability. In general, children's responses to questions of fact were more stable than responses to questions of opinion. The findings suggest that when questionnaires are carefully developed, school-age children are reliable respondents.

Patterns of fecal coliform contamination in day-care centers.

During a six-month period, on four separate occasions, six licensed day-care centers had cultures taken from environmental surfaces as well as the hands of children and teachers. Fecal coliforms were recovered from 64 (9.5%) of the 675 surfaces sampled. Recovery rate was not influenced by a center's socioeconomic status, time of year, or presence of children who were not toilet trained. Recovery rates did differ significantly in different areas, with the kitchen showing a relatively high recovery rate (19%), and toys and toilets showing remarkably low rates (2% and 4%). Centers with formal hand-washing procedures had lower recovery rates than those without such practices. We also demonstrated a high recovery rate from hands of staff (16%); 6% of children had positive cultures. Contamination of hands and classroom objects is a potential source for the transmission of enteric diseases for children in day-care centers. A program directed at reducing contamination would be important in preventing the spread of diarrheal illness.