Use and abuse of psoralens.
The psoralens 1 are furocoumarins to which most people in the United States have been exposed. Celery contains psoralen. Oil of bergamot, widely used in perfumes, contains 5-methoxypsoralen. Thus, there are few persons who have not ingested psoralen and probably no adult woman who has not applied a psoralen to her skin. Plants containing psoralen have been used to produce pigmentation for at least 3,000 years. Recently, oil of bergamot has been used for this purpose. Scientific investigation of the psoralens began when Kuske 2 and, later, Fahmy and his group 3 isolated the active chemicals from a variety of plants. Many physicians in different countries began to study these compounds. Lerner, Denton, and Fitzpatrick 4 and Kelly and Pinkus 5 initiated clinical evaluation in the United States. The chemical alterations in the psoralesn which occur after oral ingestion or topical application to the skin are not known. Exposure of
Clinical and Experimental Studies with 8-Methoxypsoralen in Vitiligo1
Reports on the effective treatment of vitiligo have created great interest among physicians. El Mofty (1, 2) found that the use of crystalline constituents of the plant Ammi Majus Linn., together with ultraviolet light exposure, resulted in repigmentation of vitiliginous areas in over 75 per cent of patients with this disorder.
Dating of Historical Manuscripts Using Spectrometric Methods: A Mini-Review
An overview is provided of spectrometric methods useful for age estimation of historical manuscripts (medieval ones in particular), in order to confirm their authenticity. Individual methods (infrared and Raman spectroscopy, mass spectrometry, atomic emission spectroscopy, X-ray spectroscopy, and electron scanning microscopy) are discussed and examples of their application described. The following general strategy can be recommended for dating and/or authenticating of historical manuscripts. First of all, the pigment analysis should be carried out using Raman spectroscopy (distinguishing the period and modern pigments), followed by PIXE ink analysis (solving the question of ink homogeneity). Finally, the radiocarbon dating of the writing support, potentially supplemented by the ink dating using scanning Auger microscopy should be performed.