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Biomedical subjects

T K Hunt

Publications and source records attributed to T K Hunt.

At least 145 records · Page 8Linked to original sources
PubMed1982

Isolation of a nonmitogenic angiogenesis factor from wound fluid.

Angiogenesis, or new capillary growth, is essential to normal growth and wound healing. It is also active in several pathologic states, including the growth of malignant tumors. An extracellular, nonneoplastic angiogenesis factor has been isolated from cell-free rabbit wound fluid by pore-limit dialysis and chromatography on a size-exclusion HPLC column. The isolated angiogenesis factor was purified 9,600-fold with a yield of 81% and has a molecular weight between 2,000 and 14,000. Wound fluid angiogenesis factor was completely separated from the mitogenic activity of wound fluid; it did not increase the number of capillary endothelial cells in vitro or stimulate [3H]thymidine uptake by these cells. The isolated angiogenesis factor stimulated endothelial cell migration in vitro, and less than 200 ng of the factor stimulated angiogenesis in vivo in the corneal implant assay.

Angiogenesis Inducing Agents↗
PubMed1982

Role of platelets and fibrin in the healing sequence: an in vivo study of angiogenesis and collagen synthesis.

UNLABELLED: The signals that initiate repair are poorly characterized. These studies investigate the capacity of platelets and fibrin to initiate angiogenesis, fibroplasia, collagen synthesis and monocyte migration in the rabbit cornea assay. METHODS: Autologous platelets and platelet-free fibrin were isolated from rabbit blood. Released and control platelet preparations and autologous and commercial fibrin were implanted in rabbit corneas. RESULTS: Thrombin-released platelets produced angiogenesis and opacification. Histology showed fibroplasia, corneal thickening, and neovascularization. Collagen synthesis was elevated to twice control levels in thrombin-activated platelet preparations. Various control platelet preparations produced no angiogenesis, no opacification, and no histologic change. All fibrin injections elicited a cellular exudate from the limbal vessels, followed by angiogenesis and corneal opacification. Histology showed a mononuclear infiltrate with neovascularization and fibroplasia. Control injections of rabbit skin collagen and fibroblasts produced no response.

Animals↗
PubMed1982

Effects of caffeine-free diet on benign breast disease: a randomized trial.

There is considerable interest in the potential effect on benign disease of a diet free of methylxanthines (caffeine, theophylline, and theobromine) found in coffee, tea, colas, and chocolate. We randomly assigned 158 women who presented with a breast concern either to a group encouraged to abstain from methylxanthine-containing foods and beverages or to a group who received no dietary recommendations (controls). At the initial visit each patient's sociomedical history and data on methylxanthine consumption were obtained by interview, and clinically palpable breast findings were graded on a scale of 0 to 4 (no nodularity to confluent hard "dysplasia") for each quadrant of both breasts. On the follow-up visit approximately 4 months later similar information was obtained. Mammograms were taken at both visits for a subset of women in each group. We found a statistically significant reduction in clinically palpable breast findings in the abstaining group as compared with controls, but the absolute change was minor and may be of little clinical significance. Comparison of before-after mammograms offered little support for the methylxanthine hypothesis. There was no relation between clinically palpable breast finding scores at initial examination and caffeine consumption levels reported at that time.

Adult↗
PubMed1981

Surgical wound infections: an overview.

There have been three major avenues by which control over infection has been increased: (1) Preservation of host defenses, (2) antisepsis and (3) asepsis. Despite the major successes we have had, infection remains the major limitor of surgical horizons. Asepsis, the newest but long the mainstay of infection control, has probably been developed to nearly its greatest capacity. Its forefronts lie in laminar flow ventilation, ultraviolet radiation and operating theater design, all expensive and relatively inefficient. Cost and the problem of endogenous bacteria limit further advances. Antisepsis, including preventive antibiotics, is also reaching its zenith. Resistant organisms, toxicity and cost limit further applications. We desperately need a "social contract" among surgeons to limit, by defined rules, the choice of agent, the total dose and the indications for use. Controlled studies of the effects of "preventive antibiotics" on hospital ecology and infection are needed. A return to antiseptics is being and should be explored. Preservation and enhancement of host defenses is the oldest but the most neglected of these ideas. It appears to be the most exploitable now. Enhancement by nutrition, maintenance of tissue perfusion, oxygenation and immune stimulation appear to have contributed to reduction of infection rates. More success in this area seems distinctly possible.

Anti-Bacterial Agents↗
PubMed1981

Regulation of wound-healing angiogenesis-effect of oxygen gradients and inspired oxygen concentration.

Tissue hypoxia is a well-known stimulus to angiogenesis. The central dead space in healing wounds has been shown to be hypoxic (PO2 = 1 to 10). Angiogenesis is a necessary component of all healing wounds. Rabbit ear chambers were used to explore the contribution of O2 gradients and various inspired oxygen concentrations on wound healing and angiogenesis. These experiments demonstrate that: (1) A hypoxic tissue gradient is mandatory for wound-healing angiogenesis, (2) when the hypoxic gradient is destroyed capillary growth cases, and (3) inspired oxygen concentrations affect the rate and density of capillary growth.

Animals↗
PubMed1981

Epidemiology of breast fluid secretion: association with breast cancer risk factors and cerumen type.

The epidemiology of breast fluid secretion was studied on the basis of nipple aspirates of breast fluid obtained from 3,929 nonlactating women of various racial groups. The results confirmed and extended earlier findings by our group: Variation in the proportion of secretors was related to most breast cancer risk factors, including age, race, age at menarche, age at first pregnancy, age at menopause, clinically diagnosed fibrocystic disease, menopausal estrogen use, and cerumen phenotype. Secretory activity as measured by nipple aspiration appeared to reflect hormonal and genetic effects on breast epithelium.

Adolescent↗
PubMed1980

Laparotomy as a precipitating factor in the rupture of intra-abdominal aneurysms.

Previously asymptomatic aneurysms in ten patients ruptured within 36 days (mean, ten days) of a prior laparotomy. The laparotomy and associated intra-abdominal disease may have precipitated rupture of the unresected abdominal aneurysms by reduction of the collagen content of the aneurysm wall, thus making the wall weaker. The scar-like collagen fibers of an aneurysm wall provide the strength that permits the wall to resist rupture. There is a dynamic equilibrium between synthesis and lysis of this collagen. Lysis of collagen is enhanced by injury, such as laparotomy, and by nutritional depletion and local inflammation. Collagen lysis is greatest in the area adjacent to the injury, but also occurs at remote sites as well. Lysis is greatest during the first postoperative week, after which, in the absence of sepsis or starvation, synthesis exceeds lysis and the equilibrium is restored. A thin aneurysm wall may be weakened enough during this period of negative collagen balance to allow rupture.

Aged↗
PubMed1979

Self-surgery.

Explore the source record for details and available documents.

Abdomen↗
PubMed1979

Deficient collagen formation by obese mice in a standard wound model.

Poor healing was demonstrated in two different experimental models of diabetes mellitus. In one model, there was an absolute lack of insulin and in the other, a resistance to insulin. A review of the history of the results of surgery in diabetic patients shows that in the clinical situation, wound failure is associated with both a lack of insulin and a resistance to insulin. Thus, the causes of wound failure in diabetic patients include a failure of insulin to perform its normal role in healing. This does not exclude other causes such as "small vessel disease" as etiologic factors, but it does suggest that control of metabolic derangements is beneficial to healing in diabetic patients who undergo operation.

Animals↗
PubMed1979

Wound healing and aging.

There are "natural delays" in the healing of older individuals. Open wounds contract more slowly and incised wounds gain strength more slowly. Experimental studies indicate that cellular proliferation, wound metabolism, and collagen remodeling occur later in old animals. Clinical studies show, however, that operations can be performed safely in elderly patients and that the major increased risk to these patients is of nonwound medical complications that affect the wound.

Age Factors↗