PubMed Health⌕ Search

Biomedical subjects

W G Bardsley

Publications and source records attributed to W G Bardsley.

78 records · Page 5Linked to original sources
PubMed1970

A reinvestigation of the substrate specificity of pig kidney diamine oxidase.

1. The substrate specificity of pig kidney diamine oxidase was reinvestigated with a purer enzyme preparation than has previously been used for this purpose. 2. All substrates were extensively purified before use, and methods of preparation or sources are given, together with R(F) values. 3. The substrate specificity determined differed somewhat from that reported by previous workers and, in addition, the behaviour of several compounds not previously used as substrates is described. 4. A model for enzyme-substrate interaction embodying these observations is formulated. It is suggested that a negatively charged substrate-binding group is situated at 6.0-9.0 A from the oxidizing site. The binding and oxidizing sites are separated by a hydrophobic or methylene-binding site.

Amine Oxidase (Copper-Containing)↗
PubMedDate not supplied

Molecular charge effects on the protein permeability of the guinea-pig placenta.

The effect of molecular charge on protein permeability of the dually perfused guinea-pig placenta has been investigated by measurement of the permeability surface area products (PS) and observation of the ultrastructural localization of cationic horseradish peroxidase (cHRP) and anionic horseradish peroxidase (aHRP) molecules. Steady-state PS calculated from the experimental data was 0.032 +/- 0.0045 and 0.0045 +/- 0.0008 ml min-1 (mean +/- s.e.m.) for cHRP and aHRP respectively (P less than 0.01). The PS for a diffusional marker, 51Cr-ethylenediaminetetraacetic acid, showed no significant difference between the two groups. Ultrastructurally, placentae perfused with cHRP showed fewer microvilli and a dilated interstitial space compared with placentae perfused with aHRP; large vacuoles were also found in the syncytiotrophoblast in the former but not in the latter tissue. Reaction product in placentae perfused with cHRP was localized to the maternal-facing plasma membrane of the syncytiotrophoblast, in vacuoles and vesicles of the syncytiotrophoblast, and also in the basement membrane of the interstitial space, whereas placentae perfused with aHRP only had reaction product in vesicles in the syncytiotrophoblast. These results suggest that anionic sites in the guinea-pig placenta affect its permeability to charged proteins, cationic molecules inducing structural changes associated with increased permeability.

Animals↗
PubMedDate not supplied

Fetal and maternal blood volumes in shed human placentae: discrepant results comparing morphometry to haemoglobin content.

The maternal blood volume (MBV) and fetal blood volume (FBV) of shed human placentae delivered by caesarean section at term were measured using a morphometric technique and from the placental content of adult and fetal haemoglobin. MBV was 35.3 +/- 1.5 (s.e.m.) per cent by the former and 11.0 +/- 1.5 per cent by the latter technique. FBV was 11.0 +/- 0.7 and 9.0 +/- 0.6 per cent respectively (n = 6). Measurement of the dimensions of individual villi initially photomicrographed in 0.9 per cent NaCl and subsequently re-photographed in fixative suggested that individual villi shrank to 0.7 of their initial volume during fixation. It is suggested that morphometric measurement of MBV may lead to approximately a threefold overestimate because of relative MBV expansion and villous tissue shrinkage during the process of fixation without alteration in overall placental volume.

Blood Volume↗
PubMedDate not supplied

Quantitative analysis of wound healing.

In this article, we initially review several problems associated with the design and interpretation of certain types of experiments currently used to study wound healing, drawing attention to the fact that applications for standard statistical techniques in the analysis of the experimental results are often of limited value. We then argue that, because of the special nature of wound healing data, curve fitting of empirical model equations can often provide a convenient way to summarize treatment effects with large data sets. The various ways in which this technique could be used to facilitate the interpretation of experimental wound healing results are then explored. To illustrate this approach, we then took several wound healing experiments and introduced possible models that could be used, paying particular attention to simple equations with the smallest possible number of parameters. For each equation, the way that the parameters of the model could be interpreted with regard to the biologic effects represented is given. Examples are given to show the application of each model discussed theoretically in the interpretation of some typical experimental data sets.

Journal Article↗