J Cerottini | PubMed Health

PubMed2000

[Erythema migrans with multiple lesions].

INTRODUCTION: Erythema migrans with multiple lesions is observed in Europe in only 5-20 p. 100 of Borrelia infections. The number of lesions observed simultaneously in one patient is less than 7, considering all the cases published in the literature to date. CASE REPORTS: We report three patients who presented multiple macular, erythematous and centrifugal lesions localized on the trunk and the limbs. The first patient presented about thirty lesions, the second more than seventy, and the third about twenty. Serology investigation and immunoblots allowed to establish the diagnosis of a recent Borrelia Burgdorferi infection, with multiples lesions of erythema migrans. PCR performed on a skin biopsy of one of the patients confirmed the presence of Borrelia burgdorferi. Response to antibiotic therapy was immediate in all 3 patients. DISCUSSION: These 3 cases are of particular interest because the number of simultaneous lesions is much higher than what is reported in the European literature. These observations remind the clinician that the diagnosis of erythema migrans with multiple lesions should be included, in Europe as well, in the differential diagnosis of multiple annular dermatoses.

Adult↗

PubMed1996

Melanoma cell expression of Fas(Apo-1/CD95) ligand: implications for tumor immune escape.

Malignant melanoma accounts for most of the increasing mortality from skin cancer. Melanoma cells were found to express Fas (also called Apo-1 or CD95) ligand (FasL). In metastatic lesions, Fas-expressing T cell infiltrates were proximal to FasL+ tumor cells. In vitro, apoptosis of Fas-sensitive target cells occurred upon incubation with melanoma tumor cells; and in vivo, injection of FasL+ mouse melanoma cells in mice led to rapid tumor formation. In contrast, tumorigenesis was delayed in Fas-deficient lpr mutant mice in which immune effector cells cannot be killed by FasL. Thus, FasL may contribute to the immune privilege of tumors.

Animals↗

PubMed1976

Increased cytolytic T lymphocyte activity induced by 2-mercaptoethanol in mixed leukocyte cultures: kinetics and possible mechanisms of action.

The 20- to 50-fold increase in cytolytic T lymphocyte (CTL) activity caused by the addition of 50 muM 2-mercaptoethanol (2-ME) at the onset of a one-way murine mixed leukocyte culture (MLC) between C57BL/6 and DBA/2 splenic lymphocytes appears to be unrelated to early events in the culture: if 2-ME was present for the first 24 hr of culture only, there was no increase on day 4, but if addition of 2-ME was delayed until the last 24 hr of culture, the CTL activity was almost as high as that of cultures that were exposed to 2-ME for the entire 4-day culture period. The increase of CTL activity caused by delayed addition of 2-ME ("2-ME rescue") was used to investigate the mechanism by which the thiol induces differentiation of CTL from precursor cells. 2-ME rescue was mimicked by two other thiols, dithiothreitol and cysteamine phosphate, but at higher concentrations. Because the latter compound has no free sulhydryl group until it diffuses into cells and is enzymatically dephosphorylated, we conclude that thiols may increase the differentiation of CTL from precursor cells by an intracellular process involving free sulphydryl groups rather than by interaction with membrane sulfhydryls or destruction of inhibitor cells or their products. Cell separation experiments indicated that 2-ME rescue was independent of the presence of B lymphocytes and of adherent cells (macrophages) and was restricted to a subpopulation of T lymphocytes that developed into large lymphoid precursor cells during the first 3 days in culture even without 2-ME. The development of this subpopulation required DNA synthesis between 24 nad 72 hr after the onset of MLC. When 2-ME was added to day-3 MLC, CTL activity increased slightly as early as 4 hr later, but the major increase occurred during the second half of the 24 hr "rescue"period. Because this increase was inhibited by cytosine arabinoside (ARA-C), it seems likely that DNA synthesis is associated with and may be required for the differentiation of large precursor lymphoid cells into CTL after the addition of 2-ME.

Animals↗