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T R Jackson

Publications and source records attributed to T R Jackson.

60 records · Page 4Linked to original sources
PubMed1976

Incubation of double labelled coproporphyrinogen with chicken red cell haemolysates, chemical and TLC fractionation of extracts.

Further evidence is presented for the enzymic conversion of protoporphyrinogen to protoporphyrin by observing the loss of 3H counts by 3H and 14C labelled coproporphyrinogen when incubated in chicken red cell haemolysates. Use was made of chemical and TLC fractionation of porphyrin extracts after incubation and a loss of half the 3H was again found. Evidence is presented for the role of harderoporphyrinogen as a natural intermediate in this conversion. The relevance of the findings in the porphyrias, and in particular variegate porphyria, is discussed. It is suggested that the enzymic process involved in the conversion of protoporphyrinogen to protoporphyrin may be deficient in variegate porphyria.

Animals↗
PubMedDate not supplied

Applications of hierarchical image segmentation techniques: aorta segmentation.

The segmentation of objects from complex images is difficult due to indistinct boundaries between objects and similarity of objects. We have used a hierarchical segmentation approach to accurately distinguish between objects and identify the corresponding boundaries. This approach has been used successfully to extract the aorta from transverse magnetic resonance (MR) images of the abdomen. The procedure to segment the abdominal aorta involves three progressive steps: aorta detection, aorta extraction, and estimation of the aorta wall boundary. Comparison of hierarchical segmentation techniques with single-step segmentation methods (e.g., region-growing, edge-detection) shows that hierarchical segmentation yields more reliable results.

Aorta, Abdominal↗
PubMedDate not supplied

Users of free treatment slots at a community-based methadone maintenance clinic.

At a community-based methadone clinic in Seattle, WA, 360 opiate-addicted individuals were enrolled in a treatment demonstration project. The treatment slots were free to clients and, unlike other funded treatment slots, did not require proof of eligibility based on documentation of indigence. The clients were compared with 70 clients enrolled in a research project begun 2 years earlier in which the sample was drawn from a population using normal funding sources at the same program. Subjects in the later demonstration project were older and had fewer years of education. A higher percentage of the demonstration project subjects were African American. These differences indicate that introduction of free treatment opened opportunities to individuals who have difficulty accessing treatment under normal circumstances. Subjects in the treatment demonstration project were more likely to have obtained needles from legal sources and used bleach to clean needles. These findings probably reflect the impact of needle exchange and outreach programs, established in the year prior to the demonstration project.

Acquired Immunodeficiency Syndrome↗