Several investigations reported modulation of lymphocyte functions following activation of the histamine H2 receptor. However, few data have accumulated with regard to the distribution of histamine H2 receptors on different lymphocyte subsets. Conversely, the distribution of histamine H1 receptors on different lymphocyte subsets has been thoroughly analyzed using specific radioligands, whereas the functional significance of histamine H1 receptor ligation on lymphocytes has not been fully elucidated yet. Recent investigations suggest that H1R signaling on lymphocytes may enhance whereas activation of the H2R may inhibit lymphocyte responses. In this review, the authors discuss the current knowledge on distribution and functional significance of histamine H1 and histamine H2 receptors on human lymphocytes.

Animals↗

PubMedDate not supplied

Pemphigus--paradigm of autoantibody-mediated autoimmunity.

Pemphigus encompasses a group of life-threatening autoimmune blistering diseases due to a loss of adhesion between keratinocytes, called acantholysis, which is caused by autoantibodies (AAb) against intercellular adhesion structures of epidermal keratinocytes. In pemphigus vulgaris (PV), the blisters are located in the suprabasal layer whereas in pemphigus foliaceus (PF), a clinically less severe disease, the blisters occur within the upper layers of the epidermis. In PV and PF, the AAb target the extracellular portions of desmoglein 3 (Dsg3) and Dsg1, respectively. AAb production in PV and PF is polyclonal and most AAb are of the IgG4 subclass in acute onset or active disease while patients in remission have mainly AAb of the IgG1 subtype. Evidence for the pathogenicity of these circulating AAb is provided by the observations that (1) the activity of pemphigus correlates with AAb titers, (2) newborns of mothers with active pemphigus temporarily exhibit blisters due to the transplacentar transfer of maternal AAb and (3) pemphigus-like lesions are induced in neonatal mice by transfer of IgG from PV patients. Clinically, pemphigus is characterized by extensive cutaneous blisters and erosions of the mucous membranes (PV). Patients with untreated pemphigus are prone to infections, loss of body fluids and proteins and to weight loss due to painful oral and esophageal erosions. The major therapeutic strategy in pemphigus is chronic immunosuppressive therapy with glucocorticosteroids in combination with immunosuppressive adjuvants.

Animals↗

PubMedDate not supplied

Lymphocyte activation in allergic reactions elicited by small-molecular-weight compounds.

The involvement of cytochrome-P450-dependent metabolism of small-molecular-weight compounds as a prerequisite for an optimal lymphocyte response to those compounds is discussed on the basis of studies with compound such as p-phenylenediamine, sulfamethoxazole, chloramphenicol and fragrances. Subsequently, data on cytochrome P450 activity and CYP gene expression in monocytes and MAC-6 cells for cytochromes P450 2E1 and 3A4 are presented.

Chloramphenicol↗

PubMedDate not supplied

History and present organization of pediatric oncology in Germany.

Explore the source record for details and available documents.

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