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Chitosan-mediated tight junction disruption is caused by a translocation of tight junction proteins from the membrane to the cytoskeleton.

Leg ulcers present a common and recurring problem in older people creating discomfort and distress for the patient and a great cost to the health care services. Cultured keratinocyte grafts have been used by many investigators to stimulate healing of chronic venous ulcers. It has been proposed that they may do this by producing cytokines which modulate the healing process. However, the types and levels of cytokines in the leg ulcer fluid before and during healing are not known. Wound fluid was collected from venous leg ulcers in 18 patients beneath occlusive Tegaderm dressing for 4 to 6 h. The leg ulcers were divided on clinical criteria into 'healing' and 'non-healing'. PDGF-AB, GM-CSF, IL-1 alpha, IL-1 beta, IL-6 and bFGF were measured by ELISA and the levels of IL-1 alpha, IL-1 beta and IL-6 were also measured using biological assays. The effect of leg ulcer wound fluid on fibroblast and keratinocyte proliferation was measured indirectly by 3H-thymidine incorporation and MTT assay. Total protein, albumin levels, fibronectin degrading activity and collagenase activity, both active and latent were measured. No statistically significant differences in the levels of cytokines or collagenase were identified between healing and non-healing leg ulcers in the sample of leg ulcers studied. However, this study does give valuable information concerning the levels of cytokines and collagenase in chronic leg ulcer wound fluid.

Although acne has traditionally been viewed as predominantly affecting adolescents, a significant and growing body of literature suggests an adult (i.e. post-adolescent) form of the disease. This review summarizes selected publications on post-adolescent acne, and discusses possible causes and treatment options. Recent epidemiological studies show that there appears to be an increase in post-adolescent acne, and that the disease is lasting longer and is requiring treatment well into the mid forties. There is good agreement that, unlike teenage acne, where males tend to show the most severe forms of the disease, post-adolescent acne mainly affects females (the lesions are frequently perioral and occur premenstrually) and that there are two forms of the disease. The terms 'persistent' and 'late onset' are now generally accepted as describing these two types. The causes of post-adolescent acne remain to be fully elucidated and hormones, colonization by resistant bacteria and the use of cosmetics have been put forward and debated in the literature. Additionally, some clues to the cause of post-adolescent acne may be gleaned from an individual's response to therapy. Perhaps one of the most intriguing explanations for the increase in this disease is the proposed relationship between increasing stress levels, androgen hormones and increasing levels of acne found in women in fast paced jobs.

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