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Biomedical subjects

R Tucker

Publications and source records attributed to R Tucker.

At least 19 recordsLinked to original sources
PubMed1992

The human carotid atherosclerotic plaque stimulates angiogenesis on the chick chorioallantoic membrane.

The chick chorioallantoic membrane was used to determine whether the carotid atherosclerotic plaque stimulates angiogenesis. Carotid endarterectomy specimens (1 mm3) with fibromuscular plaque (n = 8) and complicated plaque (n = 11) were implanted on the membrane on day nine of incubation and the response evaluated on day 11. Following fixation in situ with 10% formalin the angiogenic response was evaluated by: (1) examining whole membrane mounts, (2) quantitatively from a vascular density index and (3) from a histological study. Unmanipulated chorioallantoic membrane (n = 11) and plaque boiled prior to implantation (n = 6) served as controls. The vascularity of whole mounts of both fibromuscular and complicated plaque was greater than the controls. Vessel density of the membrane was estimated by counting the number of vessels intersecting four concentric circles (144.5 mm total circumference) placed on the formalin fixed membrane. The vascular density index due to the fibromuscular plaque (390.6 +/- 8.3) and complicated plaque (391.0 +/- 14.9) were similar (P greater than 0.9) but were significantly greater (P less than 0.001) than the unmanipulated membrane (327.9 +/- 5.6) or after treatment with the boiled plaque (283.8 +/- 15.6). Transforming growth factor beta 1 confirmed the validity of the experimental model to study angiogenesis. The histology of the chorioallantoic membrane due to either type of plaque was similar. Numerous vessels surrounded the plaque, and intraplaque vessels containing nucleated chick erythrocytes were observed. Although scattered vessels surrounded the boiled plaque, intraplaque vessels were not observed. This study demonstrates that the atherosclerotic plaque has angiogenic properties that may account for the increase in vasa vasorum that is associated with the plaque.

Allantois↗
PubMed1991

The effect of PDGF on the healing of full thickness wounds in hairless guinea pigs.

1. Platelet-derived growth factor (PDGF), administered daily for 5 days and every other day for 9 additional days or the day of wounding and the following day, caused dose dependent (0.2, 1.0 or 5.0 micrograms PDGF/wound) increased granulation tissue. 2. The two day 5.0 micrograms treatment resulted in a 73% increase and the multi-day treatment resulted in a 52% increase of alkaline phosphatase activity three days after wounding. 3. Multi-day treatment resulted in significant increases in protein synthesis (132%), vimentin content (160%) and excised wound weight (76%) three days after wounding. 4. These results indicate that limited administration of PDGF alters wound healing although multiple applications provoke a more dramatic response.

Alkaline Phosphatase↗
PubMed1990

Autoantibody production by severe combined immunodeficient mice reconstituted with synovial cells from rheumatoid arthritis patients.

In an attempt to characterize the heterogeneity of the human autoantibody response, mice with severe combined immunodeficiency were reconstituted with synovial or blood lymphocytes from patients with rheumatoid arthritis (RA). Mononuclear cells extracted from synovial fluid or tissue (SMC) were a greatly enriched source of IgM rheumatoid factor (RF)-producing cells compared to the peripheral blood mononuclear cells (PBMC) of rheumatoid arthritis patients or normal donors. Six to nine weeks after reconstitution of mice with synovial mononuclear cells, 0%-39.3% (mean = 11.4%) of total IgM consisted of IgM RF compared to 0%-0.15% (mean = 0.02%) in mice given RA PBMC and 0%-1.2% (mean = 0.34%) in mice given normal PBMC. Detectable levels of IgM RF were maintained in some mice for as long as 20 weeks after transfer. Mice reconstituted with synovial membrane or synovial fluid lymphocytes produced a heterogeneous mixture of immunoglobulins. These included other autoantibodies, such as anti-nuclear and anti-cytoplasmic antibodies, and antibodies to exogenous antigens such as the Epstein-Barr virus nuclear antigen-1 (EBNA-1). This heterogeneity is further illustrated by the demonstration that the sera from mice given synovial cells also contained IgG antibodies possessing all three major VH families (VH1, VH3 and VH4) and the four major V kappa families (V kappa 1 to V kappa 4). Autoantibody production gradually decreased with time even under circumstances where total immunoglobulin levels increased, and elevated production could not be induced by antigenic stimulation. These findings describe a new model for the analysis of human autoantibody production.

Animals↗
PubMed1990

Nursing care of the patient with non-Hodgkin's lymphoma. A case study.

A patient's significant life events, such as the diagnosis of cancer, coupled with critical developmental milestones provide particular challenges to nurses caring for young adults. A case study format is used to identify nursing care priorities throughout the diagnosis and treatment of a young adult male with non-Hodgkin's lymphoma. Diagnosis and treatment protocols are discussed to provide a background for nursing assessment and interventions. Nursing implications related to the treatment protocol are incorporated as are implications based on the physical and psychological impact of the disease and necessary life-style changes. Stressors created by the disease and treatments are identified, and the support of patient coping strategies and continued achievement of developmental tasks are addressed.

Adult↗
PubMed1990

Non-Hodgkin's lymphoma. Understanding the disease.

An overview providing current knowledge about non-Hodgkin's lymphoma (NHL) is presented. The pathophysiology, epidemiology, clinical signs and symptoms, and the classification system of NHL are outlined. In addition, the staging of NHL, diagnostic procedures, treatment options, and recommendations related to follow-up care and managing recurrent disease are presented.

Adult↗
PubMed1989

Sulfation pharmacogenetics: correlation of human platelet and small intestinal phenol sulfotransferase.

Phenol sulfotransferase (PST) catalyzes the sulfate conjugation of phenolic drugs. All human tissues studied contain a thermostable (TS) form of PST, which catalyzes the sulfate conjugation of "simple" phenols such as p-nitrophenol, and a thermolabile (TL) form, which catalyzes the sulfation of dopamine and other monoamines. In the present study we tested the hypothesis that genetically controlled levels of TS and TL PST activity in the platelet, as well as inherited variations in the thermal stability of platelet TS PST, might reflect those same characteristics of the enzyme in the less accessible tissue, human small intestinal mucosa. Platelet TS and TL PST activities and TS PST thermal stability were measured in blood samples from 45 randomly selected healthy subjects, and 14 of those subjects were selected to have intestinal biopsies performed. There was a significant correlation between levels of platelet and jejunal mucosal TS PST activity (rs = 0.574, p less than 0.030), but there was not a significant correlation between levels of TL PST activity in the two tissues (rs = 0.265, p = 0.368). There was also a significant correlation between the trait of TS PST thermal stability in the two tissues (rs = 0.828, p less than 0.0001). These observations suggest that inherited variations in TS PST activity and thermal stability in an easily obtained tissue, the platelet, might be used to predict individual differences of those properties of the enzyme in the human small intestine, an organ that plays an important role in drug metabolism.

Adult↗
PubMed1989

An examination of loneliness among elderly Canadian seasonal residents in Florida.

As part of a larger study focusing on different facets of the lives of 2,731 older Canadians who seasonally reside in Florida, we investigated primarily the extent of family and friendship contacts and the loneliness expressed by these older Canadians. The data were collected using a questionnaire that was distributed and returned by mail. The sample was taken from the subscription list of a newspaper in Florida that was a subsidiary of a large Canadian newspaper. The results show a population that was relatively young, married, in generally good health, and with rather extensive contacts with family and friends while residing in Florida. Nevertheless, more than a fifth indicated they were at least somewhat lonely. Results, using discriminate function analysis, showed that those more lonely were younger, female, less educated, not married, in poorer physical health, had fewer Florida friends, and had more children who lived near them in Canada, but fewer children who lived near them in the United States. Implications of the results are discussed.

Age Factors↗
PubMed1975

The surface of the pecten oculi in the pigeon.

A scanning electron microscopic study of the pecten reveals the rib-like character of the pectinal folds, the nature of their connections with the base and bridge of the pecten as well as the presence of interconnections between the bundles of superficial collagenous fibers. It has been suggested that the pecten may have a mechanical significance, namely protection of the retina from the excessive movements of the vitreous humour. The relationship between the superficial membrane of the folds which is continuous, the intercellular spaces and the process of diffussion has also been discussed.

Animals↗