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Biomedical subjects

J J Hutchinson

Publications and source records attributed to J J Hutchinson.

7 recordsLinked to original sources

Irradiation induces upregulation of CD31 in human endothelial cells.

Radiation-induced vascular injury is believed to be a major factor contributing to parenchymal atrophy, fibrosis and necrosis in normal tissue after radiotherapy. In this study irradiation of human umbilical vein endothelial cells (HUVECs) significantly increased adherence of U-937 cells in a time-dependent manner. Given the potential multifunctional role of CD31 in the vasculature we have examined the possible effects of irradiation on levels of CD31 expression in HUVECs. Irradiation upregulated CD31 expression on HUVECs, independently of initial plating density and radiation-induced changes such as cell number, cell cycle stage, or cell size. CD31 mRNA levels were raised in irradiated HUVECs relative to controls. Both CD31 mRNA and surface protein showed similar changes, suggesting that the increase in mRNA in irradiated HUVECs is responsible for the elevation in cell surface protein. A semi-quantitative study of tissue specimens from patients who had received radiotherapy indicated that CD31 staining in the blood vessels from irradiated tissues was increased compared with controls. Endothelial CD31 is important in the transmigration of leukocytes. We have demonstrated that the incorporation of monoclonal antibody to CD31 significantly inhibited the transmigration of human peripheral blood leukocytes through a monolayer of irradiated HUVECs. Taken together these data strongly suggest that irradiation induces a marked increase in CD31 expression on endothelial cells as part of a general response to irradiation. Its upregulation may play an important role in the development of radiation-induced normal tissue damage and thus is a possible target for therapeutic intervention.

Alternative Splicing↗

Prospective, multicenter study of managing lower extremity venous ulcers.

Seventy patients with 90 venous ulcers were randomly assigned to hydrocolloid or conventional dressing and compression therapy at four study centers. The ulcers had been present for a mean of 47.8 in the control and 46.2 weeks in the treatment group and 42% of all patients had recurrent ulcers. Ulcers treated with hydrocolloid dressings reduced 71% and control treated wounds reduced 43% in area after 7.2 weeks of treatment. Thirty-four percent of all ulcers healed. Mean time to healing was 7 weeks for the hydrocolloid dressing group and 8 weeks for the control group. Most ulcers were less painful at final evaluation, but reduction in pain was more pronounced in hydrocolloid-dressed ulcers (p = 0.03). At baseline as well as during follow-up, significant differences between study centers were observed. Ulcers in patients in the United Kingdom were larger and less likely to heal (p = 0.001). Size of the ulcer at baseline was associated with treatment response and time to healing (p = 0.002). Percent reduction in ulcer area after 2 weeks was also correlated with treatment outcome (p = 0.004) and time to healing (p = 0.002). When all treatment outcome predictors were analyzed together, only percent reduction in area after 2 weeks remained statistically significant (p = 0.002), with percent reduction during the first 2 weeks of treatment > 30% predicting healing.

Aged↗

Microbiology and healing of the occluded skin-graft donor site.

Delayed healing of skin-graft donor sites may be costly and life-threatening, especially in patients with large body surface area burns. A donor site dressing should maximize the ability of the wound to heal without increasing the risk of local infection, systemic infection, or both. Specifically, the possibility of a secondary infection may either slow the healing process or ultimately convert the donor site into a full-thickness skin loss. A number of materials ranging from gauze to biologicals have been investigated for use as donor site dressings. The use of hydrocolloids for donor sites has been widely studied and has shown improved healing rates over the rates reported for conventional dressings. Our recent study using hydrocolloids confirmed earlier research that showed fewer infections and more rapid donor site healing.

Burns↗

Wound infection under occlusive dressings.

It is often supposed that occlusive dressings potentiate wound infection. However, even though heavy colonization by skin and wound flora is often seen under certain types of occlusion, clinical infection is not a frequent occurrence. Commensal wound flora consists of a variety of Gram-positive and Gram-negative organisms and fungi which do not appear to be detrimental to healing. Certain aspects of wound healing may in fact be promoted by bacterial colonization, although clinical infection can lead to wound breakdown and systemic infection. Wounds compromised by devitalized tissue, drains or sutures are more susceptible than clean wounds to clinical infection. Occlusive dressings may help prevent infection by presenting a barrier to potential pathogens, and hydrocolloid occlusive dressings have been shown to prevent dissemination of methicillin-resistant Staphylococcus aureus. The rate of clinical infection as deduced from published trials of dressings is lower under occlusion than when non-occlusive dressings are used, and this is likely to be a result of normal activity of the host defences under occlusive dressings.

Bacteria↗

Occlusive dressings: a microbiologic and clinical review.

This review discusses the microbiology of normal skin and wounds and examines the rates of infection reported under both conventional (nonocclusive) dressings and all occlusive dressings, together with cost factors. The overall infection rate under conventional dressings was 7.1% in 1085 wounds, whereas under occlusive dressings on 3047 wounds the rate was 2.6%. In studies in which the two dressing types were directly compared, the respective rates were 7.6% and 3.2%. The reasons for this difference may include both dressing-specific and host-specific factors, and these factors are discussed.

Biological Dressings↗

Intracellular killing of Candida albicans by human polymorphonuclear leucocytes: comparison of three methods of assessment.

Three different methods, [3H]uridine uptake, viable count and 51Cr-release were used to assess the intracellular survival of a strain of Candida albicans, 19321, which was lethal for mice injected intravenously. Intracellular survival 1 h after ingestion ranged from 50 to 80% depending on the method employed and the detergent used to lyse the phagocytes. Inhibition of uridine uptake by detergents used to lyse the phagocytes led to difficulty in assessment of intracellular killing by this method.

Candida albicans↗