Lymphocyte subpopulations in Lynch syndrome II: an immunocytochemical study on gastrointestinal biopsies. Preliminary report

Gastrointestinal biopsies from 18 members of a family with Lynch Syndrome II were evaluated and immunocytochemical studies were made to characterize the phenotypic expression of the tissue's immune populations. The intestinal findings suggest polyclonal B-cell activation related to the T-helper distribution. Our evaluation provides no specific information so far on the management of patients with Lynch Syndrome II.     

Neuroendocrine carcinoma of the skin (Merkel cell carcinoma): immunocytochemical study of a case

The immunocytochemical phenotype was evaluated in a case of Merkel cell carcinoma of the skin. Intermediate filaments, i.e. neurofilament, glial fibrillary acid protein, cytokeratins, keratin and panfilament as well as S-100 protein, calcitonin and epithelial membrane antigen were detected by immunoperoxidase methods. Nodular positivity for neurofilament was observed. The remaining intermediate filaments and other markers were negative. Thus the origin of Merkel cell carcinoma appears uncertain and this tumor probably has neuroendocrine activity.     

Roles of turnover and repair of macromolecules and supramolecular structural components

Macromolecules and supramolecular structural components that are incorrectly synthesized or are damaged by radiation or by reactive chemicals are either repaired or selectively degraded and resynthesized. In addition, turnover rates for macromolecules and supramolecular structures can be elevated by alternation of fasting and feeding periods and can be influenced by metabolic regulatory mechanisms which are governed by steady-state concentrations of labile macromolecules.     

On-line high-performance liquid chromatography-fluorescence detection-electrospray ionization-mass spectrometry profiling of human milk oligosaccharides derivatized with 2-aminoacridone

A high-resolution normal-phase high-performance liquid chromatography-fluorescence detection-electrospray ionization-mass spectrometry separation and structural characterization of the main oligosaccharides along with lactose from human milk samples is described. A total of 22 commercially available oligosaccharides were fluorotagged with 2-aminoacridone and separated on an amide column and identified on the basis of their retention times and mass spectra. Derivatized species having mass lower than approximately 800 to 900 exhibited mainly [M-H](-1) anions, oligomers with mass up to approximately 1000 to 1100 were represented by both [M-H](-1) and [M-2H](-2) anions, and oligomers greater than approximately 1200 to 1300 were characterized by a charge state of -3. Furthermore, the retention times were directly related to the glycans' molecular mass. Human milk samples from the four groups of donors (Se±/Le±) were analyzed for their composition and amount of free oligosaccharides after rapid and simple prepurification and derivatization steps also in the presence of lactose in high content. This analytical approach enabled us to perform the determination of species not detected by traditional techniques, such as sialic acid, as well as of species present in low content easily mistaken with other peaks. Finally, labeled human milk oligosaccharides were analyzed without any interference from excess fluorophore or interference from proteins, peptides, salts, and other impurities normally present in this complex biological fluid.