Evidence for alpha-MSH binding sites on human scalp hair follicles: preliminary results.

Alpha-MSH, considered an important pigmentation hormone, binds to melanocytes and is thought to stimulate melanogenesis through a cyclic-AMP-dependent mechanism. The binding of alpha-MSH to follicular melanocytes has been investigated in human hair of different colors, ranging from black to blond and senile white. Hairs were plucked, the follicles were cut off, and an alpha-MSH binding assay, using a radiolabeled alpha-MSH analogue, was performed on these bulbs. As controls of each assay, fragments of hairs of the same person were used. The results show a dose-response relationship and the assay seems to be specific for alpha-MSH, because other peptides such as ACTH, beta-LPH and beta-endorphins do not compete for binding sites as alpha-MSH does. These binding sites seem to be present only on melanin synthesizing melanocytes, since the controls and follicles of senile white hair, which do not contain active melanocytes, show negative results. All the assays were performed on raw material, i.e., whole plucked hair follicles. This is the first time that binding sites for alpha-MSH have been demonstrated on human scalp hair follicles. In addition, their presence was found to be associated with active melanin production; their absence was demonstrated on senile white hair follicles.

Grafting of venous leg ulcers. An intraindividual comparison between cultured skin equivalents and full-thickness skin punch grafts.

Skin equivalents that consisted of a noncontracted collagen gel populated with allogeneic fibroblasts and covered with autologous cultured keratinocytes were used for grafting venous leg ulcers. The results were compared in the same patient with those obtained with a routinely used standard method of grafting with autologous full-thickness punch grafts. The skin equivalents and the punch grafts were grafted successfully in four of five patients. The median healing time of ulcers grafted with skin equivalents was 18 days whereas that of ulcers covered with punch grafts was 15 days. The cosmetic appearance of the skin equivalent-grafted ulcers was better than that of the punch-grafted ulcers.

Low prevalence of coagulation and fibrinolytic activation in patients with primary untreated cancer.

The prevalence of subclinical coagulation abnormalities greatly differs in the various studies due to selection of patients and differences in study design. We performed coagulation studies in 69 consecutive patients with primary untreated cancer of various origin. The control group consisted of 42 sex and age matched healthy volunteers. Plasma coagulation tests included thrombin-antithrombin-III-complex (TAT), plasmin-alpha 2-antiplasmin-complex (PAP) and tissue-plasminogen-activator-antigen (t-PA-ag). These tests were performed once, prior to any anti-cancer treatment. We evaluated if activation of the coagulation system (elevated TAT-complexes) and the fibrinolytic system (elevated PAP-complexes and t-PA-ag) correlated with the tumor-type or the extent of the tumor. To document clinical manifest haemorrhage or thromboembolic disease (TED) we performed a 6 months follow-up study. In 8 patients (12%) and in 3 control subjects (7%) an elevated TAT-complex level was observed (this difference is not significant). An increased plasma level of PAP-complex was seen in 8 patients (12%) versus none in the control group (p less than 0.05). In one patient both TAT and PAP-complex concentrations were elevated. Consequently, 15 of the 69 patients (22%) showed activation of the coagulation and/or fibrinolytic system. Fibrinolysis seems to be enhanced in a subset of cancer patients in contrast to blood coagulation. In 10 patients (14%) we found raised t-PA-ag levels. Three patients had both elevated levels of PAP-complex and t-PA-ag. These findings suggest that in a minority of patients increased PAP-complex levels may be a result of t-PA induced plasminogen activation.(ABSTRACT TRUNCATED AT 250 WORDS)