Portfolio as a method for continuous assessment in an undergraduate health education programme.

A portfolio assessment system has been introduced into a biomedical science programme to promote both continuous learning and deep approaches to learning. Attention has been focused on creating harmony between the assessment system and the PBL curriculum of the programme. Biomedicine and laboratory work are central in the curriculum.

Biosynthesis of mucins in bovine trachea: identification of the major radiolabelled species.

Bovine trachea in organ culture secretes mucus containing a 'high-density' (1.46 g/ml) and a 'low-density' (1.37 g/ml) mucin similar to those identified previously in bovine respiratory secretions [Hovenberg, Carlstedt and Davies (1997) Biochem.

Mucus glycoproteins in bovine trachea: identification of the major mucin populations in respiratory secretions and investigation of their tissue origins.

Bovine respiratory secretions were separated into gel and sol phases to allow the identification of the gel-forming mucins. Mucins were subsequently isolated from the surface epithelium and submucosal tissue to investigate the tissue origins of the species in the secretions. Density-gradient centrifugation revealed 'high-density' and 'low-density' mucins in the gel phase of the secretions.

MUC5AC, but not MUC2, is a prominent mucin in respiratory secretions.

Airway mucus was collected from healthy and chronic bronchitic subjects. The chronic bronchitic sputum was separated into gel and sol phase by centrifugation and mucins were isolated using isopycnic density-gradient centrifugation in CsCl. The presence of the MUC5AC and MUC2 mucins was investigated with antisera raised against synthetic peptides with sequences from the respective apoproteins.

Different mucins are produced by the surface epithelium and the submucosa in human trachea: identification of MUC5AC as a major mucin from the goblet cells.

Mucins were extracted from the epithelial surface and the submucosal tissue of human trachea in order to enrich glycoproteins from the goblet cells and the submucosal glands respectively. The macromolecules were purified using density-gradient centrifugation, and the presence of the MUC5AC mucin was investigated using an antiserum raised against a synthetic peptide based on the sequence of the MUC5AC apoprotein. Mucins from the surface epithelium showed a higher reactivity with the antiserum relative to carbohydrate than those from the submucosa, and ion-exchange HPLC of reduced subunits revealed the presence of two distinct mucin populations in the samples.