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Biomedical subjects

R W Stoddart

Publications and source records attributed to R W Stoddart.

At least 73 records · Page 4Linked to original sources
PubMed1978

Saccharide distribution in human trophoblast demonstrated using fluorescein-labelled lectins.

The reaction of six Flourescein-conjugated lectins with human trophoblast and foetal limb are described. The trophoblast had marked membrane fluorescence after treatment with wheatgerm and Lotus tetragonolobus lectins. Concanavalin A reacted strongly with the trophoblastic cytoplasm but did not react with the nuclei. Most of the lectins had only weak reactions with foetal tissue, apart from the cartilage matrix which fluoresced strongly after treatment with several of the lectins. In addition, concanavalin A reacted with amylase-labile material, probably glycogen, in the skin epidermis and chondrocyte cytoplasm. Various substances were tested in order to determine the nature of the wheatgerm lectin receptor of trophoblast. Several secretory and binding proteins were found not to be responsible, and the identity of the receptor remains unknown.

Carbohydrate Metabolism↗
PubMed1978

The use of fluorescein-labelled lectins in the detection and identification of fungi pathogenic for man: a preliminary study.

Fluorescein-labelled lectins of known specificities for different sugars were used in an attempt to identify fungi in paraffin sections of surgical and post-mortem material. Aspergillus fumigatus, Blastomyces dermatitidis, Candida albicans, Cryptococcus neoformans, Paracoccidioides brasiliensis and Rhizopus oryzae have been studied with five fluorescein-labelled lectins and with basis of differences in their reactions with these stains. The results accord well with what is known of the chemistry of the organisms and the method offers promise to practising histopathologists.

Aspergillus fumigatus↗
PubMed1976

Changes in the organs of pigs in response to feeding for the first 24 h after birth. III. Fluorescence histochemistry of the carbohydrates of the intestine.

The duodenum, jejunum, ileum and large intestine of newborn, and 24-hour-old fed and unfed piglets, and of 10-day-old piglets have been studied by new histochemical methods. At birth Meissner's plexus was most developed in the duodenum. There was little change during the first 24 h, but by 10 days it had become elaborated. Goblet cells were present at birth in all parts of the intestine. After 24 h a large proportion of those in the duodenum had discharged and were being replaced with a new generation. Similar changes took place more slowly in the jejunum and ileum and very much more slowly in the large intestine. Feeding increased the rate of turnover.

Animal Nutritional Physiological Phenomena↗
PubMed1969

Solution properties of polygalacturonic acid.

1. The specimen of polygalacturonic acid used in these studies was shown to contain very little neutral sugar, methyl ester groups or ash, and only residues of galacturonic acid. Its electrophoretic homogeneity was examined in pyridine-acetic acid buffer at pH6.5 and in borate buffer at pH9.2. The distribution of effective particle weights was shown to be fairly narrow. 2. The pH-titration curve of the polymer gave a pK value of 3.7. 3. The interaction of the polymer with Ruthenium Red was studied and titration curves were obtained for the spectral shifts associated with the formation of a complex. 4. Optical-rotatory-dispersion studies showed that the Drude constant, lambda(c), was dependent on pH. 5. Polygalacturonic acid was shown to display non-Newtonian properties in solution and to have an anomalously high relative specific viscosity at low concentrations. 6. Studies were made of the pH-dependence of the sedimentation coefficient of the polymer. 7. These results are discussed in terms of the structure of the molecule and their relevance to the properties of pectic substances.

Buffers↗