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Biomedical subjects

A Häffner

Publications and source records attributed to A Häffner.

8 recordsLinked to original sources
PubMed2003

Proteus syndrome.

A 34-year-old male patient was referred with a recalcitrant leg ulcer overlying an extensive vascular malformation, which had led several times to septic soft tissue infections. During his infancy he had been diagnosed to have Klippel-Trenaunay syndrome. Clinical examination revealed asymmetric hypertrophy of the lower extremities, an extensive portwine stain on the more severely affected left limb as well as prominent venous varicosities of both legs. Hands and feet showed striking cerebriform palmoplantar hypertrophy, and macrodactily with syndactily of several fingers. All toes had been amputated in early childhood due to extreme overgrowth and currently the patient walked on his forefeet in a prominent pes equinus deformity. Further symptoms consisted in several lipomas at both arms, another portwine stain at the left hemithorax and a single café-au-lait spot at the left scapula. Angio-magnetic resonance imaging scans of both legs showed an extensive venous-lymphatic vascular malformation involving the whole subcutis and infiltrating the muscle. The chronic wound was interpreted as venous stasis ulceration. Local percutaneous sclerotherapy of the dilated veins underneath the ulcer was discussed, but considered to carry a relevant risk of skin necrosis with consecutive progression of the wound. A conventional split-skin graft led to complete wound healing. Since, the patient consequently wears custom-made compression stockings and remained free from recurrences. The syndromatic constellation of palmoplantar overgrowth, multiple lipomas, giant fingers and toes, limb overgrowth, venous-lymphatic malformation and a café-au-lait spot led to the diagnosis of Proteus syndrome. The possible aetiology, clinical manifestations, differential diagnosis and management of this rare disorder are discussed.

Adult↗
PubMed2003

Therapy of cutaneous lymphoma--current practice and future developments.

Cutaneous lymphomas include various types of clonal lymphoproliferative disorders. The adequate treatment approach depends on the exact diagnosis and should be non-aggressive in most cases. In early stages, local approaches such as UV or radiotherapy are preferred. In advanced stages, systemic drugs such as interferon-alpha or bexarotene can be administered. Experimental approaches for cutaneous lymphomas include vaccination and gene therapy.

Humans↗
PubMed2001

The interferon inhibiting cytokine IK is overexpressed in cutaneous T cell lymphoma derived tumor cells that fail to upregulate major histocompatibility complex class II upon interferon-gamma stimulation.

Cutaneous T cell lymphomas are characterized by an accumulation of malignant clonal lymphocytes in the skin and occasionally in the blood. We compared gene transcription profiles from cultured clonal lymphocytes with autologous healthy blood lymphocytes by microarray hybridization. Cutaneous T cell lymphoma derived cells transcribed high amounts of an interferon inhibiting cytokine factor. The presence of an interferon inhibiting cytokine factor was confirmed in 12 skin biopsies of mycosis fungoides and Sézary syndrome derived blood lymphocytes by reverse transcriptase-polymerase chain reaction. The presence of interferon inhibiting cytokine factor mRNA in Sézary syndrome derived lymphocytes was associated with a lack of HLA class II upregulation after stimulation with interferon-alpha and interferon-gamma. This was not due to a loss of the interferon signaling cascade as the presence of interferon-signaling components was confirmed by reverse transcriptase--polymerase chain reaction on the transcriptional level. The elevated constitutive interferon inhibiting cytokine factor expression observed in cutaneous T cell lymphoma derived cells was insensitive to interferon-gamma stimulation, but was enhanced in normal peripheral blood mononuclear cells. We suggest that interferon inhibiting cytokine factor contributes to the lack of HLA class II upregulation in lymphoma cells. Interferon inhibiting cytokine factor may participate in providing a microenvironment at the tumor site insensitive to interferon-gamma stimulation and thus prevents an efficient local immune response.

Adult↗
PubMed1997

Induction of biologically active IL-1 beta-converting enzyme and mature IL-1 beta in human keratinocytes by inflammatory and immunologic stimuli.

IL-1beta, a major mediator of inflammatory and immunologic skin disease, undergoes post-translational site-specific cleavage by a novel cysteine protease termed IL-1beta-converting enzyme (ICE). Although in human skin keratinocytes produce significant amounts of the 31-kDa IL-1beta precursor protein, they fail under nonpathologic conditions to convert it to the 17.5-kDa bioactive form. In this study, we examined whether haptens and inflammatory agents might serve as stimuli for ICE activity in human keratinocytes, and, if so, whether ICE activity might precipitate enzymatic processing of IL-1beta to its 17.5-kDa form. Baseline levels of ICE mRNA were detected in keratinocyte cultures devoid of Langerhans cells and were up-regulated by nontoxic concentrations of the reactive hapten urushiol and by the irritant chemicals sodium lauryl sulfate and PMA. Although untreated keratinocytes expressed the 31-kDa form of the protein, 17.5-kDa IL-1beta was easily detected in keratinocytes and keratinocyte supernatants treated with either urushiol or the irritant chemicals. Enzymatic conversion from the 31-kDa to the 17.5-kDa form of IL-1beta was blocked by addition of a highly specific aldehyde inhibitor that contained a tetrapeptide recognition sequence specific for ICE, but not by an aldehyde inhibitor of a related ICE-like cysteine protease. Induction of IL-1beta-converting enzyme by immunologic and inflammatory stimuli may be one of the key regulatory elements in the pathogenesis of allergic and irritant contact hypersensitivity.

Caspase 1↗
PubMed1996

In situ changes in the relative abundance of human epidermal cytokine messenger RNA levels following exposure to the poison ivy/oak contact allergen urushiol.

Abstract: Epidermal keratinocytes in culture have been shown to produce many cytokines, and their proteins have been identified in skin tissue samples. It has therefore been assumed that these cytokines are transcribed in vivo by the epidermis in response to contact allergens. In this report, in situ hybridization was used to detect the messenger RNAs for interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta) and tumour necrosis factor-alpha (TNF-alpha) in samples of human skin prior to and at various times after application of urushiol, the immunogenic component of poison ivy/oak. In sensitive subjects, IL-1 alpha and TNF-alpha mRNAs showed a progressive increase in transcript levels that paralleled the clinical and histological features of the inflammatory process. The time-course of the IL-1 beta response differed from that of IL-1 alpha and TNF-alpha, in that there was an early (by 6 h after urushiol administration) elevation in IL-1 beta mRNA that occurred before there was evidence of inflammation and had returned to background levels by 72 h when the reaction had reached its peak. In contrast to urushiol-sensitive subjects, urushiol-anergic individuals did not exhibit an increase in IL-1 alpha, IL-1 beta or TNF-alpha mRNA levels. The data provide evidence for an in vivo role for epidermal IL-1 alpha, IL-1 beta and TNF-alpha transcription in the regulation of IL-1 beta and TNF-alpha polypeptide levels in the epidermis in response to this common contact allergen.

Adult↗
PubMed1995

New perspectives in experimental and clinical research for cutaneous T cell lymphomas.

Cutaneous T cell lymphomas (CTCL) are lymphoproliferative disorders, which can be classified by an adaptation of the Kiel classification. The most common CTCL, Mycosis fungoides (MF) and Sézary syndrome (SS), are monoclonal T helper memory lymphomas. They belong to the group of peripheral T cell lymphomas. However, CTCL includes other disease entities such as granulomatous slack skin, pagetoid reticulosis, and lipotropic CTCL. Polymerase chain reaction of the T cell receptor (TCR)-gamma and screening of the PCR products for sequence-specific mobility in acrylamide gels has increased the detection limit for clonal T cells in the skin. This method will help to define the relationship of CTCL to other lymphoproliferative disorders and may contribute to the early diagnosis of CTCL. In SS, the malignant CTCL clone secretes a T helper-2 cytokine pattern, which might be responsible for the systemic immunosuppression in CTCL patients. New treatment modalities (IL-12) might correct these immunologic abnormalities. Cutaneous B cell lymphomas mostly are follicular center cell derived and usually have a good prognosis. Therapy of cutaneous lymphomas should take into account prognostic factors, the most reliable of which in CTCL is the tumor mass expressed by the tumor burden index.

Cytokines↗