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Biomedical subjects

G Byrne

Publications and source records attributed to G Byrne.

At least 73 records · Page 4Linked to original sources
PubMed1988

Porky's pig out.

Explore the source record for details and available documents.

Animals↗
PubMed1988

Spatial patterns in the fruiting bodies of the cellular slime mold Polysphondylium pallidum.

During morphogenesis in the slime mold Polysphondylium pallidum cell masses are periodically pinched off from the base of the developing sorogen. These masses round up and differentiate into secondary sorogens, which become radially ordered arrays of secondary fruiting bodies called whorls. Here we describe the morphogenesis of P. pallidum and characterize the spacing of whorls along the central stalk of the fruiting body and the spacing of sorocarps within whorls. We find both are highly regular. We propose that the linear spacing of whorls can be accounted for satisfactorily by a model that views the periodic release of cell masses from the base of the developing sorogen as the consequence of an imbalance between forces that orient amoebae toward the tip of the culminating sorogen, and cohesive forces between randomly moving cells in the basal region of the sorogen, which act as a retarding force. The orderly arrangement of fruiting bodies within whorls can be explained most easily by models that employ short-range activation and lateral inhibition.

Cell Differentiation↗
PubMed1987

Genesis of a spatial pattern in the cellular slime mold Polysphondylium pallidum.

The branches in Polysphondylium pallidum whorls are arranged in a radial pattern. We have used a pattern-specific monoclonal antibody to study branch formation and characterize the origin of this pattern. A quantitative spatial analysis of antibody staining reveals that the branching pattern arises from a random distribution. This distribution passes through a series of intermediate stages to yield a radial prepattern. The origins and evolution of this prepattern are satisfactorily accounted for by models that produce spatial patterns by short-range autocatalytic and longer-range inhibitory forces.

Antibodies, Fungal↗
PubMed1986

Spatial patterning in Polysphondylium: monoclonal antibodies specific for whorl prepatterns.

In this report we describe three monoclonal antibodies which detect prepatterning events preceding the appearance of visible tips in Polysphondylium pallidum whorls. A spatial and temporal analysis of the antigens against which these antibodies are directed reveals that the radial distribution of arms within whorls has its origins in an initial global amplification of tip-specific antigens over the surface of very early whorl masses. This two-dimensional distribution becomes restricted with time to a single dimension, a smooth distribution of antigen in a band about the equator of the whorl mass. This equatorial distribution breaks up into patches which eventually become visible tips. These results reveal that a spatial pattern can arise from a smooth prepattern, and grow through a series of intermediates characteristic of the symmetry breaking model first described by A. Turing (1952).

Antibodies, Monoclonal↗
PubMed1982

Sinus histiocytosis with massive lymphadenopathy: a case with unusual skin involvement and a therapeutic response to vinblastine-loaded platelets.

A patient with sinus histiocytosis with massive lymphadenopathy had unusual skin lesions and progressive internal involvement. Both aspects responded dramatically to the administration of vinblastine-loaded platelets. Vinblastine-loaded, idiopathic thrombocytopenic purpura antibody-coated platelets are a rationale therapy for a disease characterized by the presence of actively phagocytosing histiocytes.

Antibodies↗
PubMed1982

In vivo and in vitro studies on the binding of salicylate to human plasma proteins: evidence for one type of binding site.

In vivo and in vitro binding of salicylate to plasma proteins was studied by ultrafiltration at room temperature. The nonlinearity of the Scatchard and Klotz plots were explained by the presence of lipid-soluble substances in plasma. Delipidation of plasma resulted in changes of the binding characteristics of plasma in that more moles of salicylate could be bound per mole of protein. This changed the appearances of the Scatchard and Klotz plots so that a much larger range of salicylate concentration could be accommodated by the linear portion of the graphs. The equilibrium constant for the in vitro salicylate binding was identical for the delipidated and untreated plasma. However, the in vivo binding constant for salicylate in plasma was higher than the in vitro binding constant.

Adult↗
PubMed1980

Social relationships, adversity and neurosis: a study of associations in a general population sample.

A standardized study of the point prevalence of non-psychotic disorder was carried out on a systematic sample of Canberra residents (N = 756). Rates were estimated for PSE CATEGO diagnoses and the Index of Definition. The association between neurosis and deficiencies in social relationships was examined, using the Interview Schedule for Social Interaction (ISSI). An objective measure of exposure to adversity was also obtained at interview. Both attachment and social integration (affectionally close and more diffuse relationships) were found to be negatively associated with neurosis. This association holds in its own right, in addition to an interaction with the load of adversity. The associations are weaker for men. The significance of this work lies in its demonstration of an association between neurosis and the lack of social ties, and in its attempt to obtain a specification of those elements in social relationships which, when deficient, may be associated with neurosis. The direction of causality has now to be investigated.

Australia↗
PubMedDate not supplied

Prognostic significance of TGF beta 1 and TGF beta 3 in human breast carcinoma.

Transforming growth factor beta s (TGF beta s) are multifunctional growth factors which show differential expression both temporally and spatially and exert pleiotropic effects during carcinogenesis. Although all three mammalian isoforms of TGF beta share considerable sequence similarity, they appear to have distinct functions in health and disease, such as embryogenesis, wound healing and tumourigenesis. Much of our knowledge about the relationship between TGF beta s and breast cancer is based on publications on TGF beta 1 but the role of TGF beta 3 in the progression of breast cancer has not been well documented. In the present study, the expression of TGF beta 1 and TGF beta 3 was assessed by immunohistochemistry. Of the 153 invasive breast cancer tissues, TGF beta 1 was expressed strongly in 25 and moderately in 98 cases. The immunoreactivity of TGF beta 3 was comparable with TGF beta 1, which was expressed strongly in 21 and moderately in 104 cases. The two isoforms were coexpressed in 111 (72.5%) tumours and were absent in 16 cases (10%). Immunostaining for TGFb3 but not TGF beta 1 was inversely correlated with overall survival (p = 0.0204). When combined with lymph node involvement, TGFb3 became an even more significant prognostic factor for overall survival (p = 0.0003), i.e. patients with node metastasis and positive TGFb3 expression had a worse prognosis: the risk of death for these patients was thirteen-fold greater than those who had no node involvement. The fact that it has been reported previously that high TGF beta 3 plasma levels in patients with untreated early stage breast cancer were correlated with subsequent lymph node metastasis and it was observed in the present study too, that TGF beta 3 expression in breast tumours was an independent predictor of overall survival, led us to suggest that the simultaneous measurement of TGF beta 3 in plasma and its expression in resected tumour tissues in the same cohort of patients may prove to be an important parameter in assessing tumour progression.

Adult↗
PubMedDate not supplied

Paracetamol availability and overdose in Ireland.

New regulations for the control of paracetamol come into force in October 2001. These are greatly welcomed and should lead to a reduction in paracetamol poisoning. Existing conditions for the sale and supply of paracetamol (Irish Medicines Board (IMB), 1997), which have no statutory basis, state that non-pharmacy outlets should only sell emergency supplies of paracetamol in a maximum pack size of 12 tablets; just one pack should be sold on each occasion2. This study found that non-pharmacy outlets do not comply with these IMB conditions. Paracetamol poisoning remains the most common form of overdose requiring hospital admission in Ireland. Admissions increased by 29% between 1993 and 1999. The new regulations will give effect to the IMB conditions.

Acetaminophen↗
PubMedDate not supplied

Influence of finish-line form on crown cementation.

Studies reporting the influence of finish-line configuration on the fit of cemented crowns have had conflicting conclusions. This study examined the effect of finish-line configuration on the fit of cemented complete crowns. Three identical tooth preparations were made, each with a different facial finish line: shoulder, shoulder-bevel, and chamber. The prepared teeth were replicated to produce 45 epoxy resin teeth, 15 for each finish-line design. Thirty cast crowns were fabricated and seated on their respective epoxy resin teeth--fifteen without cement and fifteen with zinc phosphate cement. An additional set of fifteen castings, seated on their working dies, was used for control measurements. All specimens were embedded, sectioned, and measured at predetermined sites. Results showed that finish-line form does not affect the fit of cemented crowns.

Cementation↗