PubMed Health⌕ Search

Biomedical subjects

R G Fulcher

Publications and source records attributed to R G Fulcher.

6 recordsLinked to original sources
PubMed2000

Visualizing enzyme infusion into apple tissue.

Enzymes traditionally used in food processing are applied to ground or macerated tissue with little or no retention of cellular structure. More recently developed applications use enzymes to selectively alter tissue properties while retaining some structure. Process development has been hindered by the lack of conclusive evidence showing that enzyme infusion into plant tissue pieces is possible. This study provides direct evidence that such infusion is possible by using fluorescence microscopy to monitor vacuum infusion of fluorescein-labeled alpha-amylase into apple cubes. This method is generally applicable to any plant or animal tissue and to any macromolecule capable of derivatization.

Biotechnology↗
PubMed1999

Evaluation of wheat (Triticum aestivum L.) phenolic acids during grain development and their contribution to Fusarium resistance.

The phenolic acid profiles of six cultivars of wheat with known tolerance to Fusarium head blight were evaluated during plant development from anthesis through maturity. Analysis by HPLC of grain at anthesis revealed that p-coumaric and ferulic acid were the two principal phenolic compounds present. The effect of these two phenolic acids on Fusarium species was evaluated in vitro. Both phenolic acids demonstrated significant reductions (p < 0.05) of Fusarium species growth at all concentrations tested. Ferulic acid is the primary phenolic acid in grain at all stages of development, and its concentration increased steadily during grain development prior to a 50% decrease during grain ripening. The accumulation of ferulic acid synthesis from anthesis until approximately 20 days after anthesis appears related with cultivar resistance to Fusarium. Concentrations of ferulic acid in the grain were similar at maturity, implying that the end-use quality would be similar for both resistant and susceptible cultivars.

Coumaric Acids↗
PubMed1990

An ultrastructural morphometric study of follicular center lymphocytes: III. The control of lymphocyte nuclear size in reactive hyperplasia and non-Hodgkin's lymphoma.

Since lymphocyte nuclear size and shape play such a key role in the classification of non-Hodgkin's lymphoma (NHL), the mechanisms and nuclear compartments responsible for the control of nuclear size are of fundamental importance to pathologists. To assess the role of condensed chromatin and the interchromatinic region of the nucleus in determining the size of this organelle, morphometric image analysis of total nuclear area and the area occupied by these two compartments was performed on electron micrographs of nuclear profiles from lymphocytes in lymph node biopsies of four cases of reactive lymphoid hyperplasia and ten examples of NHL. Using bivariate linear regression analysis, it was clear that, whether in normal mantle zone and follicular center lymphocytes or in the neoplastic lymphocytes of various NHLs, there is an extremely high correlation (R = 0.96) between the size of the interchromatinic region and the area of nuclear profiles. In contrast, there is a poorer correlation (R = 0.63) between the area occupied by condensed chromatin and nuclear area. The results demonstrate for the first time that even in NHL, where some nuclear features clearly vary from the normal counterpart, the control of nuclear size continues to be largely dependent on a particular subcompartment of the nucleus, the interchromatinic region. How this fact influences the categorization of subtypes of NHL for therapeutic and prognostic purposes will be an essential avenue for further investigation.

Cell Nucleus↗
PubMed1983

Dye interactions. A basis for specific detection and histochemistry of polysaccharides.

Specific histochemical staining can be related to specific interactions of dyes and polysaccharides in solution. Specificity evidently depends upon polysaccharide conformation and the need for a close "fit" between polysaccharide and ligand. As a consequence, microscopic identification of cereal beta-(1 leads to 4)(1 leads to 3)-D-glucan and beta-(1 leads to 3)-D-glucan is possible, and is demonstrated.

Benzenesulfonates↗
PubMed1976

Improved resolution in cathodoluminescent microscopy of biological material.

This paper continues work reported in an earlier paper on modification of a Cambridge Stereoscan Mk IIA to improve the quality of cathodoluminescent micrographs of biological material. In the work presently described the microscope gun has been offset laterally by 2 mm, to prevent light from the filament passing down through the column to the specimen chamber. The electron beam is brought onto the column axis by deflection coils. This modification effectively eliminates background light in the chamber, and a full parabolic mirror is fitted to maximize light collection. Results for yeasts and wheat seed sections are described.

Microscopy, Electron, Scanning↗