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Biomedical subjects

W S Gilmore

Publications and source records attributed to W S Gilmore.

31 records · Page 2Linked to original sources

The assessment of platelet derived growth factor concentration in post myocardial infarction and stable angina patients.

Platelet derived growth factor (PDGF) has been implicated in the pathogenesis of atherosclerosis. PDGF is released by aggregating platelets and monocytes which gather around sites of arterial injury. In the study reported here the concentration of plasma PDGF was measured in post myocardial infarction (MI) patients (n = 28), angina patients (n = 25), and control subjects (n = 27). Venous blood samples were taken and the concentration of PDGF determined by an enzyme linked immunosorbent assay (ELISA). Plasma PDGF concentrations were significantly higher in the post MI group compared to both the control and angina groups (P < or = 0.05). The increase in PDGF concentration may be due to increased activation of platelets or monocytes since these two cells are major sources of plasma PDGF. High concentrations of PDGF in the circulation could further accelerate the progression of the disease.

Adult↗

Reactive oxygen species inducible by low-intensity laser irradiation alter DNA synthesis in the haemopoietic cell line U937.

BACKGROUND AND OBJECTIVE: The purpose of this study was to evaluate the possible role of reactive oxygen species (ROS) in mediating previously recorded alterations in DNA synthesis, inducible by low-intensity laser irradiation (LILI), in the haemopoietic cell line U937. STUDY DESIGN/MATERIALS AND METHODS: The ability of LILI (660 nm, 12 mW, 5 kHz) to induce ROS from U937 cells was assessed spectrophotometrically at energy densities (E.D.) from 1.0 to 11.5 J/cm2. In order to assess whether laser-induced ROS could alter cellular proliferation DNA synthesis was measured post-irradiation, by the incorporation of tritiated thymidine (3H-TdR) into the cells in both the presence and absence of the antioxidant catalase (CAT). RESULTS: Detectable ROS were produced post-irradiation only from the differentiated form of the cell line. Analysis by Student's t-test for unrelated groups showed a significant difference, at E.D.s 2.9 and 8.6 J/cm2, in the extent of DNA synthesis occurring in cells irradiated in the presence of CAT or in its absence. CONCLUSION: These findings demonstrate that laser-inducible ROS can mediate laser's effects on this cell line.

Catalase↗

Dietary fish oil supplementation alters leukocyte function and cytokine production in healthy women.

The effect of low-dose fish oil supplementation on cytokines and white cell function in women was investigated. Thirty-three healthy, nonsmoking women entered the double-blind study. For 4 weeks, 2.4 g of either fish oil (n = 16) or fish oil with vitamin E (n = 17) was added daily to the subjects' otherwise unchanged diets. Venous blood samples were taken at the onset of the trial, after the supplementation period, and again after a 9-week washout period. Plasma levels of platelet-derived growth factor and myeloperoxidase were measured using immunoassays. The intracellular peroxidase content of white blood cells was measured using a staining technique. Platelet-derived growth factor levels were significantly lowered after supplementation (P < or = .05). Intracellular peroxidase was increased (P < or = .01), and extracellular myeloperoxidase levels were lowered (P < or = .05). Taken together, these results suggest that the anti-inflammatory effect of fish oil may be due at least partly to alterations in white cell function and growth factor levels.

Adolescent↗

Low intensity laser irradiation inhibits tritiated thymidine incorporation in the hemopoietic cell lines HL-60 and U937.

The purpose of this study was to determine the effect of low intensity laser irradiation (660 nm, 12 mW, 5 kHz) on tritiated thymidine incorporation in two hemopoietic cell lines, HL-60 and U937. Cells were suspended at a concentration of 1 x 10(6)/ml in their respective serum-free media and irradiated at energy densities from 1.0 to 11.5 J/cm2. Twenty-four hours after irradiation the cells were assayed for their ability to incorporate tritiated thymidine (3H-TdR) in comparison with nonirradiated cells. Analysis by two-way analysis of variance (ANOVA) for unrelated groups showed that laser irradiation at all energy densities > or = 5.8 J/cm2 produced a significant decrease in 3H-TdR incorporation (P < 0.05) into HL-60 cells. In U937 cells, irradiation at energy densities of 5.8, 7.2, and 11.5 J/cm2 caused a similar reduction in 3H-TdR incorporation (P < 0.01), although not at 8.6 and 9.6 J/cm2. The temperature of each cell suspension was recorded both during and immediately postirradiation, and no significant thermal changes were observed. These findings demonstrate a direct photobiological effect of laser irradiation on these two cell lines. The precise mechanism for this effect is unknown but may have significance in understanding the biological action of laser's known therapeutic effectiveness in promoting wound repair.

Cell Death↗

Human milk contains granulocyte colony stimulating factor.

Human milk provides the neonate with a variety of balanced nutrients and contains biologically active molecules such as hormones and growth factors. We have utilized a sensitive enzyme immunoassay to detect the granulocyte stimulator, granulocyte colony-stimulating factor (G-CSF) in human milk samples. The 12 milk samples tested contained G-CSF ranging from 45 to 1551 pg/ml.

Adult↗

Electrical stimulation of cultured myocardial cells.

This paper reports on the use of a cardiac tissue monolayer model in the investigation of some of the fundamental electrical properties of cardiac muscle. The response of cardiac tissue to increasing levels of electrical stimulus is investigated and the strength-duration curve for rectangular waveform stimulation is measured. An experimental protocol is established which provides for uniform field stimulation of the cells, and allows the cellular response (contraction) to be recorded.

Animals↗