Skin-homing CD4+ Foxp3+ T cells exert Th2-like function after staphylococcal superantigen stimulation in atopic dermatitis patients.

BACKGROUND: The effect of staphylococcal superantigens (SsAgs) on cutaneous lymphocyte-associated antigen (CLA)(+) CD4(+) Foxp3(+) T cells of atopic dermatitis (AD) patients is unknown. OBJECTIVE: To compare the effects of SsAgs on the ratio, function, and apoptosis of CCR6(+) subtype and CCR6(-) subtype of CLA(+) CD4(+) Foxp3(+) T cells among AD patients, asthma/allergic rhinitis (AR) patients without AD, and healthy subjects. METHODS: Using immunofluorescence staining followed by flow cytometric analysis, we analysed peripheral blood mononuclear cells cultured with or without staphylococcal enterotoxin B (SEB) stimulation in 20 AD patients, 20 asthma/AR patients without AD, and 20 healthy subjects. RESULTS: SEB decreased CCR6(+) /CCR6(-) ratio in CLA(+) CD4(+) Foxp3(+) T cells from AD patients and increased CCR6(+) /CCR6(-) ratio in those from healthy subjects. SEB induced the production of type 2 T helper cell (Th2) cytokine interleukin (IL)-5 in CCR6(-) subtype and anti-inflammatory cytokine IL-10 in CCR6(+) subtype of CLA(+) CD4(+) Foxp3(+) T cells. CLA(+) CD4(+) Foxp3(+) T cells from AD patients produced more IL-5 and less IL-10 after SEB stimulation than those from healthy subjects. CCR6(-) subtype of CLA(+) CD4(+) Foxp3(+) T cells from AD patients and CCR6(+) subtype of those cells from healthy subjects were more resistant to SEB-induced caspase-3 activation than the other subtype and those from other subjects. CONCLUSIONS AND CLINICAL RELEVANCE: Despite a phenotype of regulatory T cells, skin-homing CD4(+) Foxp3(+) T cells of AD patients exert effector Th2-like function after SsAgs stimulation, which may aggravate allergic skin inflammation.

Valinomycin-based K+ selective microelectrodes with low electrical membrane resistance.

A valinomycin-based membrane phase for microelectrodes with relatively low electrical membrane resistances is described. Microelectrodes with tip diameters of about 1 micron exhibit resistances of about 10(10) omega. Extremely high K+ selectivities are obtained, e.g. a rejection of Na+ by a factor of 5000 and of acetylcholine by a factor of 3400. At a constant background of 140 and 500 mM Na+, the detection limit of the K+ sensor is at 1.6 X 10(-5) and at 2.5 X 10(-5) M K+, respectively.

Clinical observations of scrub typhus on Penghu (the Pescadores Islands).

Between May and September 1973, 68 cases of scrub typhus in Chinese military personnel on the Pescadores Islands were studied. The common symptoms and signs were fever, chills, headache, eschar, myalgia, and lymph node enlargement. Most eschars were located in the axilla, waist, groin and genitals, and neck. These lesions were painless and not noticed by the patients themselves. Regional lymph node enlargement at the site of eschar drainage was common. Relative bradycardia with fever was observed in 40%, a skin rash in 35% of the patients. Leucopenia was noted more frequently in the febrile than in the convalescent stage, but more than half of the patients had a normal count. Lymphocytosis was prominent, especially during the convalescent period. An acceleration of ESR was noted. Instead of depression of the erythroid series in the marrow which was reported previously, 47% of examined patients were found to have erythroid hyperplasia. Two patients showed marked hypocellularity of the marrow in the acute febrile stage; later on became normocellular. Albuminuria was present in 15 and BUN increased in 12 patients. Elevation of serum bilirubin and SGOT was also noted. Biologic false positive VDRL tests were observed in nine patients. In 30 tests elevation of Proteus OX-K titres between 1:160 and 1:640 was noted. A geometric mean OX-K titre rise in the patients is presented; the mean titre reached a peak in the third week of illness, and then fell off. Most of the patients were treated with tetracycline 500 mg every six hours for about nine days. The fever usually subsided within 36 hours. Complications or mortality were not encountered.