Possible premalignant character of oral lichen planus the Amsterdam experience

In the present paper the 21-yr experience of the Department of Oral and Maxillofacial Surgery and Oral Pathology, and the Department of Otorhinolaryngology of the Free University Hospital, Amsterdam, is reported with regard to the possible premalignant character of oral lichen planus. The study consists of two parts: 1) the follow-up of 113 patients with histopathologically proven oral lichen planus, and 2) a search for lichen planus in 727 patients who have been admitted for oral cancer. Three patients with histopathologically proven lichen planus developed a squamous cell carcinoma in an average follow-up period of 7 yr. In the 727 patients with oral cancer, two additional patients with the simultaneous occurrence of oral lichen planus were observed. Our experience gives some but not very strong support to the hypothesis that oral lichen planus is a premalignant condition.     

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Indications for pacemaker therapy of the heart (author's transl)]

During the last few years the indications for pacemaker therapy could be extended in step with the lowering of the frequency of complications and the effort required of doctors and departments. Now one does not only aim at prevention of dangerous Adams-Stokes attacks but increasingly at improvement of the range of cardiac function. If there is no pharmacologic alternative there are no absolute contraindications. Pacemaker therapy is indicated also, if only temporary symptomatic improvement can be expected.     

Qualitative and quantitative investigations of cyclophosphamide (NSC-26271), cyclophosphamide metabolites, and related compounds by field-desorption mass spectrometry.

The potential of field-desorption mass spectrometry (FD-MS) coupled with photoplate detection for qualitative and quantitative studies on cyclophosphamide (CP) and its metabolites is reviewed. The characteristic features of this ionization mode are minimal fragmentation of the molecular ion coupled with the capacity to produce such ions from thermally unstable or nonvolatile samples. Since CP is itself extensively fragmented in the electron-impact ionization mode, and since it possesses both thermally unstable (eg, 4-hydroxycyclophosphamide, carboxyphosphamide) as well as ionic and hence nonvolatile metabolites (eg, phosphorodiamidic acid), the FD technique has potential value for the detection and quantitation of the drug and its metabolites in underviatized mixtures. Some of the factors which influence the reproducibility of FD spectra are enumerated. In order to improve the FD technique for quantitative results a device for emission-controlled FD was constructed and its use is described. Three different modes of operation are discussed using the FD spectra of CP conjugates typical for each. Preliminary investigations into the use of the d6 analog of CP for quantitation of the drug by FD-MS are also reported.