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Biomedical subjects

Dan Lipsker

Publications and source records attributed to Dan Lipsker.

At least 19 recordsLinked to original sources

p16 expression in relation to human papillomavirus in anogenital lesions.

Recent studies have revealed that cervical cancers associated with high-risk human papillomavirus (HPV) showed overexpression of the p16 protein, a cyclin-dependent kinase inhibitor. The expression of this cell cycle regulator in lesions of the anogenital region in association with HPV physical status (episomal or integrated) has not been studied at the present time. In this report, immunohistochemical analysis of p16 and HPV detection by in situ hybridization were performed on 110 formalin-fixed and paraffin-embedded samples of anogenital lesions. The results showed strong diffuse p16 staining in all integrated high-risk HPV-positive lesions, whereas most episomal HPV-positive lesions or HPV-negative lesions showed no p16 immunostaining. However, there were a few HPV-negative lesions or lesions with episomal HPV harboring p16 overexpression. On the other hand, some lesions were p16 negative while showing the presence of high-risk HPV in its episomal form. In conclusion, screening for p16 overexpression in cutaneomucous lesions of the anogenital region allowed good discrimination between HPV-integrated lesions and lesions harboring episomal HPV or no HPV. But p16 overexpression was not always predictive of the presence of high-risk HPV; moreover, absence of p16 immunostaining observed in some high-risk HPV lesions suggested that limiting the screening to p16 would exclude some patients harboring high-risk HPV from any follow-up.

Anus Diseases↗

Could Jessner's lymphocytic infiltrate of the skin be a dermal variant of lupus erythematosus? An analysis of 210 cases.

BACKGROUND AND OBJECTIVE: The objective of this study was to evaluate the relationship between Jessner's lymphocytic infiltration of the skin (JLI) and lupus erythematosus (LE), which has been the subject of debate since its initial description in 1953. MATERIAL AND METHODS: This is a retrospective study including all patients with a histopathologically ascertained diagnosis of JLI performed at the Laboratoire d'Histopathologie Cutanée of the Strasbourg University Hospital between 1993 and 2003. Information about patient characteristics and follow-up data were retrieved between 2004 and 2005. Special attention was paid to features indicative of LE. RESULTS: 210 consecutive patients (102 women and 108 men) with a mean age 42 years were diagnosed with JLI in the reference period. 175 patients (83%) had multiple lesions and 32 patients (15%) had only a single lesion at the time of diagnosis (data not available in 3 patients). The head, neck and upper part of the thorax were involved in 171 patients (81%). An annular or arciform configuration and/or arrangement were present in 111 patients (53%). Lesions consisted of red (100%) papules or plaques (98%). Mean follow-up was 4 years. Sixteen patients (7.6%) had proven LE. Only 2 patients (1%) developed >4 ACR criteria of systemic LE. Furthermore, 1 patient had antiphospholipid antibody syndrome and 2 patients had rheumatoid arthritis. CONCLUSIONS: This high frequency of patients with typical features of LE strongly argues that JLI could be a dermal variant of LE and not an autonomous entity. It might be the cutaneous marker of a subset of LE patients with excellent prognosis.

Adult↗

Reproduction of Langerin/CD207 traffic and Birbeck granule formation in a human cell line model.

Birbeck granules (BG) are organelles specific to Langerhans cells (LCs), which form where the C-type lectin Langerin accumulates. Their function remains obscure due to morphologic and dynamic alterations induced by maturation of isolated LC. In this study, we attempted to reconstitute Langerin traffic and BG formation in the endosomal pathway of a human melanoma cell line. In the selected Langerin-transfected cell line, M10-22E, Langerin is distributed between the early recycling endosomal compartment and the plasma membrane, as in LC. Whereas mainly concentrated in membranes related to the Rab11(+) endosomal recycling compartment at the steady state, Langerin also recycles in M10-22E cells and drives BG biogenesis in the endosomal recycling compartment. Interruption of endocytosis or recycling induces redistribution of intracellular Langerin with an associated alteration in BG location and morphology. We have, therefore, generated a stable, Langerin-transfected cell line in which Langerin traffic and distribution and BG morphology replicate that seen in freshly isolated LC. This practical model can now be used to further delineate the nature and function of BG.

Antigens, CD↗

Cored tubules are present in human epidermal Langerhans cells.

Cored tubules are ultrastructural organelles described to date only in murine cells belonging to the Langerhans cell family and located in the dermis and its draining lymph nodes. These organelles, the function of which is unknown, differ from Birbeck granules and are interestingly not found in murine epidermal Langerhans cells. In this work we demonstrate that cored tubules are present in freshly isolated human epidermal Langerhans cells. The tubules were found to be interconnected with structures known to belong to the early endosomal pathway and could be immunolabeled with gold-conjugated anti-CD1a and anti-Langerin monoclonal antibodies, but only at 37 degrees C. At this temperature such antibodies are able to progress from the early sorting endosomes to the early recycling endosomes, which in human Langerhans cells include the Birbeck granules. These findings strongly suggest that cored tubules form part of the early recycling compartment.

Antigens, CD↗

The AESOP (adenopathy and extensive skin patch overlying a plasmacytoma) syndrome: report of 4 cases of a new syndrome revealing POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes) syndrome at a curable stage.

We describe an easily recognizable and previously not individualized clinical syndrome that can reveal solitary plasmacytoma of bone. We report 4 patients with a slowly extending violaceous skin patch overlying a solitary plasmacytoma of bone, associated with enlarged regional lymph nodes. Biopsies of the cutaneous lesion and the lymph nodes were not specific, although increased dermal mucin deposition and vascular proliferation were present in all skin specimens. Three patients had associated polyneuropathy. One patient had POEMS (Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal protein, and Skin changes) syndrome at the time the plasmacytoma was diagnosed. Another patient developed POEMS syndrome, from which he died, 4 years after excision of the plasmacytoma. The 3 other patients were treated either with irradiation or with a combination of irradiation and surgery, and recovered completely, including from the associated neuropathy and/or POEMS syndrome. We suggest calling this unique and distinctive clinical presentation the for

Aged↗

Evidence of a trimolecular complex involving LPS, LPS binding protein and soluble CD14 as an effector of LPS response.

The kinetics of the interaction of lipopolysaccharide (LPS), lipopolysaccharide binding protein (LBP) and CD14 was studied using surface plasmon resonance. The association and dissociation rate constants for the binding of LPS and rsCD14 were 2.9 x 10(4) M(-1) s(-1) and 0.07 s(-1) respectively, yielding a binding constant of 4.2 x 10(5) M(-1). Significantly, the presence of LBP increased not only the association rate but also the association constant for the interaction between LPS and CD14 by three orders of magnitude. Our experimental results suggest that LBP interacts with LPS and CD14 to form a stable trimolecular complex that has significant functional implications as it allows monocytes to detect the presence of LPS at a concentration as low as 10 pg/ml or 2 pM, and to respond by secreting interleukin-6. Thus, LBP is not merely transferring LPS to CD14 but it forms an integral part of the LPS-rLBP-rsCD14 complex.

Acute-Phase Proteins↗