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Plant tissue analysis is a valuable tool for evaluating the nutritional status and quality of crops and is widely used for scientific and commercial purposes. The majority of plant analyzes are now performed by techniques based on ICP spectrometry such as inductively coupled plasma-optical emission spectroscopy (ICP-OES) or ICP-mass spectrometry (ICP-MS). These techniques enable fast and accurate measurements of multielement profiles when combined with appropriate methods for sample preparation and digestion. This chapter presents state-of-the-art methods for digestion of plant tissues and subsequent analysis of their multielement composition by ICP spectrometry. Details on upcoming techniques, expected to gain importance within the field of multielement plant tissue analysis over the coming years, are also provided. Finally, attention is given to laser ablation ICP-MS (LA-ICP-MS) for multielement bioimaging of plant tissues. The presentation of the methods covers instructions on all steps from sampling and sample preparation to data interpretation.

Trace elements are unevenly distributed and speciated throughout the cereal grain. The germ and the outer layers of the grain have the highest concentrations of trace elements. A large fraction of the trace elements is therefore lost during the milling process. The bioavailability of the remaining trace elements is very low. This is usually ascribed to the formation of poorly soluble complexes with the phosphorus storage compound phytic acid. Hence, analysis of the total concentration of trace elements in grain tissues must be combined with a speciation analysis in order to assess their contribution to human nutrition. This chapter deals with the fractionation of anatomically very different cereal tissues. Procedures for microscaling of digestion procedures are outlined together with requirements for the use of certified reference materials in elemental profiling of grain tissue fractions. Methods for extraction and analysis of complexes containing trace elements in the grain tissue fractions are described. Finally, the chapter concludes with criteria for choice of chromatographic methods and setting of ICP-MS instrument parameters.

The relationship between chronic pancreatitis (CP) and extrapancreatic cancer has been debated in the recent years. In prospective studies, it has been found that pancreatic cancer develops in 0-5% of patients with chronic pancreatitis. Many papers describe an increased relative risk for developing extrapancreatic cancer in patients suffering from chronic pancreatitis. In this study including 181 patients with CP, we found 14 patients with extrapancreatic cancer (three of these had two different types of cancer). No patient had pancreatic cancer. It was found that the respiratory airways and upper gastrointestinal tract were the dominating locations (five and four cases, respectively), but also genital and hemolymphopoietic cancers were represented (four and two cases, respectively). Two patients had metastatic cancer with unknown primary tumor. The patients with cancer tended to be older than those without cancer. The patients with CP had a 2.43 times greater risk of developing cancer than the general Danish population (age and sex standardized comparison). The relatively large number of cancers in the upper gastrointestinal tract and respiratory airways suggest that tobacco and alcohol may be responsible, as these organs have the highest exposure to these compounds, which are well known carcinogens.

Assembly of the class I MHC molecule is inextricably linked to the antigen presentation function of the class I molecule. Association of the class I MHC molecule with beta 2-microglobulin (beta 2m) is a prerequisite for association with the heterodimeric protein TAP, and once peptide is acquired, the class I molecule folds and begins its sojourn to the cell surface. To maintain its folded conformation, class I MHC requires peptide but not beta 2m, and the sequence of the peptide bound exercises a subtle influence on the structure of the class I molecule that is likely to be a factor in T cell receptor discrimination of MHC/peptide complexes.