Inhibition of the development of immediate hypersensitivity by staphylococcal enterotoxin B

We investigated the ability of staphylococcal enterotoxin B (SEB) to modify the immediate hypersensitivity response induced in BALB/c mice following sensitization to ovalbumin (OVA), a response mediated by OVA-reactive Vβ8 T cells. Mice were sensitized by skin painting with OVA every second day over a period of 2 weeks. SEB, a potent activator of Vβ8⁺ T cells, was administered at the same site where OVA was applied (skin of the lower abdomen) following two different protocols. In protocol (A) SEB was injected intradermally 1 day before painting with OVA and on day 7; in protocol B, SEB was injected each time OVA was applied to the skin (eight times). SEB (but not SEA) altered the development of immediate hypersensitivity to OVA, as demonstrated by the reduction in allergen-specific IgE, decreased OVA-specific immediate skin test responsiveness, and prevented the development of increased airways responsiveness after bronchial challenge with OVA. Injections of SEB did not alter the proliferative responses of local draining lymph node cells or spleen mononuclear cells to OVA, indicating that administration of SEB did not inhibit the sensitization to OVA, but shifted the immune response away from an immediate type response (IgE/IgG₁) to IgG_2a, IgG_2b and IgG₃. Although both protocols of SEB treatment did not lead to a major deletion of the Vβ8 T cell population, they did reduce the proliferative response of Vβ8⁺ T cells to OVA. These data indicate that the bacterial toxin SEB is capable of modifying the immediate hypersensitivity response induced by OVA by altering the functional capacity of antigen-reactive Vβ8 T cells.     

Characterization of monocyte-derived dendritic cells in recent-onset diabetes mellitus type 1

Dendritic cells (DC) may play an important role in the immunopathogenesis of type 1 diabetes mellitus (DM-1). In this study, we have analyzed phenotypical changes during cytokine-driven maturation from CD14+ monocytes to mature DC and DC-dependent T-cell stimulation in recent-onset pediatric DM-1 patients and healthy controls. DC maturation was monitored by flow cytometric analyses for the expression of surface markers (HLA-DR, CD1a, CD40, CD80, CD86, CD83, CD14, CD32, mannose-receptor, and CD11c). Flow cytometric analysis of isolated peripheral blood monocytes did not reveal apparent differences between patients and controls. During DC maturation no obvious differences in the expression patterns of surface markers over time or evidence for maturation impairments in DM-1 patients could be appreciated. Solely, a marginal, but significant, transient down-regulation of CD1a on Day 3 (mean MDFI 3.82 vs 7.25; P = 0.021), which was accompanied by an increase of IL-6, could be observed. The comparison of mature DCs (Day 10) between patients and controls indicated no significant differences, except for CD83 (mean MDFI 1.7 vs 1.5; P = 0.042) and CD80 (mean MDFI 15.92 vs 12.73; P = 0.042). Moreover, no difference in T-cell stimulatory capacity was seen. In conclusion, our analysis of a cohort of recent-onset DM-1 patients and controls does not support a role for disease-related alterations in cytokine-driven maturation of monocyte-derived DC.     

Reconstitution of T- and B-cell function after T-lymphocyte-depleted haploidentical bone marrow transplantation in severe combined immunodeficiency due to adenosine deaminase deficiency

A 4-month-old male received a T-lymphocyte-depleted haploidentical bone marrow transplant (BMT) for correction of severe combined immunodeficiency (SCID) due to adenosine deaminase (ADA) deficiency. Although previous haploidentical bone marrow transplants have been attempted in ADA-deficient SCID, complete reconstitution of both B-lymphocyte and T-lymphocyte function has not been obtained after a single transplant. In this patient, however, rapid, complete, and persistent engraftment occurred. Potential reasons for this successful reconstitution include the use of ablation by chemotherapy (busulfan, cyclophosphamide, and cytosine arabinoside), the in vitro technique of using monoclonal antibody (CT-2) and complement to deplete the donor cells of T lymphocytes, and the relative good health of the patient prior to the transplant. Further trials using this method of haploidentical BMT may prove it to be a successful method of immunologic reconstitution in ADA-deficient SCID patients for whom an HLA-identical marrow is not available.     

Dielectric properties of a combined main-chain/side-chain liquid-crystalline polymer

The dielectric relaxation properties of a combined main-chain/side-chain liquid-crystalline polymer were investigated. It was found that the rotation of the side chain about the main chain (δ-process) is not as strongly restricted as in side-chain liquid-crystalline polymers. This is attributed to the facts that the side chain is attached to the flexible spacer within the chain backbone and that the concentration of the side chains is comparatively small. Two low-temperature relaxation processes were observed to occur in the glassy smectic and the crystalline state. They are attributed to intramolecular motions with in the mesogenic groups.     

Verlorene Lebensjahre: Bekanntes und Neues zur Methodik am Beispiel der häufigsten Todesursachen in Deutschland

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Verlorene Lebensjahre (Years of Life Lost, YLL) sind ein aussagekräftiger, in Deutschland jedoch wenig verwendeter Indikator...     

Adolescent Substance Use Behavior Change Through School Intervention Is Improved by Teacher and School Implementation Support Together,Especially for Girls

Prevention Science - An earlier trial of a school-based, preventative intervention, HealthWise South Africa, demonstrated some efficacy in preventing adolescent drinking and smoking in the Western...     

Postoperative prognosis of pulmonary adenocarcinoma subtypes correlates with HLA-DR expression and the number of tumor-infiltrating cells

Human pulmonary adenocarcinomas (AC) can be divided into two types with special morphologic and immunohistologic properties and a different number of tumor-infiltrating cells as shown by previous investigations. In the present study the relevance of this subdivision for patients' survival was investigated. 42 surgically resected pulmonary AC of stage I and II were subclassified using light and electron microscope. For immunohistologic phenotypization, reactions with monoclonal antibodies against HLA-DR, CD1 and CD3 were studied on fresh tumor specimens. Postoperative survival was evaluated after at least 24 months. AC of type I (N=23) with mucin production and ultrastructural properties of goblet cells showed almost no HLA-DR expression. Infiltration by CD1-positive dendritic cells Langerhans cells and CD3-positive T lymphocytes was significantly lower than in AC of type II (N=19), which expressed HLA-DR homogeneously and showed, ultrastructurally, Clara cell and/or type II pneumocyte properties. Patients' outcome was similar in stage I AC of both types: about 70% of patients were still alive after 24 months. However, significant differences were found between the two types in stage II AC with regional lymph node metastases: survival of patients with AC of type II corresponded roughly with stage I tumors (67%) but only 20% of patients with type I AC were still alive after 24 months. These results indicate that postoperative prognosis for patients with pulmonary AC of type II is more favourable than for mucinous AC of type I. This may be due to the homogeneous HLA-DR expression and higher number of immunologically competent tumor-infiltrating cells which possibly results in better tumor surveillance.