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One feature of the Laser Microprobe-Mass-Analyzer (LAMMA) is the analysis of biomedical specimens. This method allows to obtain qualitative and quantitative information about the inorganic and--in a qualified sense--about the organic constituents of microvolumes of thin histological sections or of single cells (e.g. erythrocytes) with a relative sensitivity going down to the sub-ppm range. The paper describes the technical structure and features of the laser-microprobe, its advantages and possibilities, but also its limits in the investigation of biomedical specimens. This will be pointed out by some examples: 1) Analysis of blood from patients suffering from renal insufficiencies (A1 transportation, Fe/Mg ratio of erythrocytes). 2) Pb detection in fetal tissues after maternal Pb intoxication. 3) Analysis of trace elements (detection limits and superposition of organic background from embedding material). 4) Analysis of isotopes and molecules. The present contribution is not so much a discussion of medical problems, but mainly a discussion about the methodical and practical use of the laser microprobe.

The mechanisms of transport of molecules across the extravascular spaces represent an open problem. Vital microscopic results with marked proteins using the blue light luminescence technique indicate a movement of fluid along the connective tissue fibres. Furthermore, the findings suggest that the elastic fibres play an important role in this movement. It may also be possible to elucidate the extravascular pathway for molecules by means of the cathodoluminescence technique in the scanning electron microscope. The investigations were performed using the mesentery of mammalians anaesthetized by Nembutal. The biological material for cathodoluminescence applications was selected from animals without injection of luminescent dye as well as with animals following intravenous injection of marked proteins. Two techniques, critical point drying and freeze drying, were used in the preparation. Stained and unstained tissues were investigated in the scanning electron microscope with a special cathodoluminescence detector system. Simultaneously observations of the tissue surfaces were performed by means of the secondary electron or backscattered electron mode. The results obtained agree with the findings observed by the blue light fluorescence microscopy and confirm the concept of an extravascular fluid pathway along the elastic fibres in the tissue.

Fluorescein-labeled antigen-antibody complexes could be made visible by scanning electron microscopy using an intensifying device. This new method of immunocathodoluminescence was demonstrated on cryostat sections of rat kidneys containing glomerular fibrin as the result of endotoxin infusion. The resulting photographs correspond with those obtained by immunofluorescent microscopy. The advantage of this technique is, however, the larger depth of focus. By using thinner cyostat sections it is expected that the higher resolution of scanning microscopy will provide even better details in three dimensions.

In order to distinguish between different types of people endangered by alcohol, five different indicators were used to classify the degree of alcohol affinity: KFA/Feuerlein, German version of part of the Manson Evaluation, alcohol-in-blood concentration, and frequency and amount of drinking. The degree of alcohol affinity potential is quite different depending on each indicator. All indicators together discriminate between nine independent types (each for men/women) of alcohol-endangered people. Further-more, five independent drinking motivations could be factor analyzed. The diversity in this field was completed by sixteen different therapies used by physicians for alcoholism treatment.