Lichen planus: a clinical and immuno-histological analysis.

BACKGROUND: Direct immunofluorescence examination is an important technique in the diagnosis of cutaneous inflammatory disorders including lichen planus, especially in clinically and histopathological doubtful cases. OBJECTIVE: To study the diagnostic utility of intensity, number, and subtypes of positive immuno-reactants found in lichen planus. MATERIALS AND METHODS: A detailed analysis of clinical as well as immuno-histological features of lichen planus cases was carried out. RESULTS: The male to female ratio was 1:1.1. The largest number of patients was in 31-50 year age group. Itching was the most common presenting symptom. Papular lesions were seen in 53% cases. Remaining had hypertrophic (6), follicular (3) and mucosal (9) variants. Clinico-pathological discrepancies were observed in 3 patients. The characteristic histopathological changes including basal cell vacuolization, band-like lymphocytic infiltrate at dermo-epidermal junction were seen in all the biopsies while Civatte bodies were detected in 29% cases. The overall positive yield of direct immunofluorescence microscopy was 55%. Immune deposits at Civatte bodies and dermo-epidermal junction were detected in 47% and 8% of cases, respectively. Immunoglobulin M was the most common immunoreactant followed by immunoglobulin G. CONCLUSIONS: There was no correlation found between the number and intensity of Civatte bodies with clinical variants of disease and also between the number of positive immunoreactants and clinical severity of the disease. The frequency, number, and arrangement of Civatte bodies in clusters in the papillary dermis as well as multiple immunoglobulins deposition at the Civatte bodies on direct immunofluorescence of skin biopsies are important features distinguishing lichen planus from other interface dermatitis.

Pharmacological modulation of farnesyltransferase subtype I attenuates mecamylamine-precipitated nicotine withdrawal syndrome in mice.

This study was designed to investigate the effect of FTI-276 trifluoroacetate, a selective inhibitor of subtype I, on the development of the mecamylamine-induced nicotine withdrawal syndrome. Mice were administered nicotine (2.5 mg/kg, subcutaneously) four times daily for 7 days. To precipitate nicotine withdrawal, mice were administered one injection of mecamylamine (3 mg/kg, intraperitoneally) 1 h after the last nicotine injection on the test day (day 8). Behavioral observations were made for a period of 30 min immediately after mecamylamine treatment. FTI-276 trifluoroacetate treatment markedly and dose-dependently attenuated the precipitated nicotine withdrawal syndrome, measured by a composite withdrawal severity score, jumping frequency, hyperalgesia in the tail flick test, and anxiety-like behavior in the elevated plus maze test. The results suggest that FTI-276 trifluoroacetate can inhibit the development of a precipitated nicotine withdrawal syndrome, and thus that farnesyltransferase subtype I may be a viable pharmacological target to tackle the problem of nicotine addiction.

Towards an indirect screening technique facilitating detection of cellular populations bearing specific cell surface markers.

We describe and demonstrate a technique for detection of cell surface antigens, with potential use in tissue antigen research. Briefly, a small volume of wetted chromatographic beads (specifically, 100 µL of Nickel-nitriloacetic acid (NTA) agarose) was bound to small quantities (specifically, ∼0.1-0.2 µg) of a single-chain Fv antibody recognizing the Class I MHC heavy chain antigen. The beads were then used to capture and detect cells bearing this antigen, through SDS polyacrylamide gel electrophoresis of boiled bead-cell complexes. A key feature of this method is its use of "signal amplification." Although the antibody-mediated binding and immobilization of intact cells involves relatively small numbers of antibodies, and cells, what is being detected is simply the presence of cells. Each bound cell contains a number of abundant proteins that are present in millions of copies per cell, and the abundance of these proteins ensures that they are detectable on SDS-PAGE, signaling cell-binding. As few as 10(10) -10(12) scFv antibodies immobilized on 100 µL of Ni-NTA beads are thus enough for the trapping of enough cells to allow visualization of their abundant proteins. Conceptually, this method could be easily developed and applied to detection of cells bearing any other cell specific antigen.