ABSTRACT
1. Using whole-cell patch-clamp recordings of NMDA EPSCs from co-cultured rat hippocampal (CA region) neurones, developmental changes in the kinetic and pharmacological properties of synaptic NMDA receptors were investigated. During in vitro differentiation a fast decaying component increasingly contributed to NMDA EPSCs. 2. Extracellular Mg2+ (1 mM) strongly blocked NMDA EPSCs at all stages in culture. Using the NR2B subunit-specific NMDA receptor antagonist ifenprodil (3 microM), we observed a developmental decrease in ifenprodil sensitivity of NMDA EPSCs. This suggests developmental changes in the expression of NMDA receptor subtypes. 3. To transiently block presynaptic exocytosis, we incubated presynaptic explants with tetanus toxin (TeTx) prior to cultivation. In TeTx-pretreated cultures the occurrence of fast decaying components of NMDA EPSCs and the developmental decrease in ifenprodil sensitivity was inhibited. Our results indicate a regulatory role of presynaptic exocytosis in the expression of NMDA receptor subtypes.
Subject(s)
Exocytosis/drug effects , Hippocampus/metabolism , Neurons/metabolism , Receptors, N-Methyl-D-Aspartate/metabolism , Synaptic Membranes/metabolism , Animals , Coculture Techniques , Electrophysiology , Excitatory Amino Acid Antagonists/pharmacology , Excitatory Postsynaptic Potentials/drug effects , Hippocampus/cytology , Hippocampus/drug effects , Kinetics , Membrane Potentials/physiology , Neurons/drug effects , Patch-Clamp Techniques , Piperidines/pharmacology , Rats , Receptors, N-Methyl-D-Aspartate/drug effects , Receptors, Presynaptic/drug effects , Receptors, Presynaptic/metabolism , Synaptic Membranes/drug effects , Tetanus Toxin/pharmacologyABSTRACT
The differential diagnosis of seronegative polyarthritides are manyfold and can cause problems even for the routine rheumatologist. Together with the symptom "fever of unknown origin" an intensive diagnostic workup is often unavoidable. Five patients with this symptom combination are discussed who also had different typical manifestations of the adult onset Still's disease (AOSD).
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Anti-Inflammatory Agents/therapeutic use , Still's Disease, Adult-Onset/drug therapy , Adolescent , Adult , Antirheumatic Agents/therapeutic use , Azathioprine/therapeutic use , Chloroquine/therapeutic use , Diagnosis, Differential , Female , Humans , Male , Middle Aged , Organogold Compounds , Steroids , Still's Disease, Adult-Onset/diagnosisABSTRACT
A female patient presented with the typical clinical and histological features of disseminated lupus erythematosus (LE). Direct immunofluorescence, as well as antinuclear antibodies were negative, but antibodies directed against the cytoplasmic Ro-antigen were found. The Ro-antigen is regarded as highly specific for SLE and Sjögren's syndrome. Clinical features and diagnosis of this distinct LE subset ("ANA negative, anti-Ro-positive LE"), as well as the sensitivity and specificity of the substrate in ANA determinations are discussed.
Subject(s)
Antibodies, Antinuclear/immunology , Autoantigens , Isoantibodies/immunology , Lupus Erythematosus, Systemic/immunology , RNA, Small Cytoplasmic , Ribonucleoproteins , Adult , Antigens/immunology , Chloroquine/therapeutic use , Female , Humans , Lupus Erythematosus, Systemic/drug therapyABSTRACT
Annular elastolytic giant cell granuloma (AEGCG) is a clinical and histological entity, which has been described previously in various different terms. Knowledge of AEGCG is of importance, since its misdiagnosis may lead to improper therapy; e.g. longterm tuberculostatic or corticosteroid treatment. In the present paper two patients with typical AEGCG are described and the clinical and histological differential diagnosis is discussed in detail.
Subject(s)
Granuloma, Giant Cell/pathology , Skin Diseases/pathology , Skin/pathology , Aged , Biopsy , Diagnosis, Differential , Female , Humans , Lupus Vulgaris/diagnosis , Necrobiosis Lipoidica/diagnosis , Sarcoidosis/diagnosisABSTRACT
A 27 year old women revealed chronic relapsing, spontaneously developing hematomas without coagulopathy. The lesions were reproducible by intradermal injection of erythrocyte membranes as well as DNA. Positive test reactions could be elicited or suppressed by psychological influences on the patient. This case and similar reports in the literature raise the question whether Gardner-Diamond syndrome and the autosensitization to DNA are different entities.
Subject(s)
Psychophysiologic Disorders , Purpura/psychology , Adult , DNA/administration & dosage , DNA/immunology , Erythrocytes/immunology , Female , Humans , Immunization , Psychophysiologic Disorders/pathology , Purpura/immunology , Purpura/pathology , Skin TestsABSTRACT
Eccrine porocarcinoma is an extremely rare malignant skin tumor arising from the eccrine sweat duct unit (acrosyringium). It presents histologically with nests of clear tumor cells in the epidermis and superficial dermis. In addition such clear tumor cells lie isolated high up in the epidermis, closely resembling Paget cells. The various tumors, which may originate from the acrosyringium and the histologic differential diagnosis of eccrine porocarcinoma are discussed.