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Biomedical subjects

E Mian

Publications and source records attributed to E Mian.

13 recordsLinked to original sources

Collagen as a pharmacological approach in wound healing.

The authors have reviewed the most important biological mechanisms involved in wound healing, the main agents that modify the healing process and the physiological and pharmacological role of collagen. Putative mechanisms of collagen in wound repair are described with particular emphasis on haemostatic effect, interaction with platelets and fibronectin, properties of of increasing fluid exudate and its cellular component (macrophages) and the "scaffold" role for fibroblastic proliferation. Experimental and clinical data clearly suggest that the potential use of collagen in wound repair and its main therapeutical applications: treatment chronic leg ulcers and pressure sores, burns, urological surgery, gynaecological surgery, dentistry and oral surgery, reconstructive surgery, abdominal and vascular surgery, orthopaedy.

Biological Dressings↗

Healing of open skin surfaces with collagen foils.

Applications of Condress (patented sheets of pure bovine collagen) on open skin surfaces (30 cases of "ulcus cruris", 5 cases of decubitus, and malum perforans; 10 cases of full-thickness burns) were examined in a controlled trial. Quantification of regeneration speed, macrophotographic survey of granulation tissue and epithelial border, thermographic and chromometric evaluation of the skin microcirculation, and histological observation of regenerating tissues, were the parameters used. The following results were obtained: marked reduction of healing time, different aspects of the granulation-tissue responses, different times of topical collagenolysis, increased vascular perfusion, histological activation of angiogenesis, fibrogenesis, histiomacrophage function and superficial absorption. The employment of Condress in burn areas seems to be highly promising.

Biological Dressings↗

High testosterone levels of ovarian origin affect adrenal steroidogenesis?

Androgens of ovarian origin have been suggested to affect adrenal enzymatic activity. To investigate this possibility, the 17-hydroxyprogesterone (17-OH P) and cortisol (F) responses to an ACTH stimulation test (0.25 mg iv, bolus) were evaluated in 10 normal women and in 39 hyperandrogenic women with normal (14 subjects) or high (25 subjects) testosterone (T) levels. The 17-OH P release and the ratio between 17-OH P and F release in response to the ACTH stimulation test were significantly higher (P less than 0.05) in hyperandrogenic women with high T levels than in normal subjects. Eight hyperandrogenic women with high T received intranasal GnRH agonist (Buserelin, 1200 micrograms/day) for 4 weeks, and the 17-OH P and F release in response to the ACTH stimulation was reassessed after agonist treatment. At the end of GnRH agonist administration the mean circulating levels of T were significantly reduced (P less than 0.05). The F response to the ACTH test was not modified by pretreatment with the GnRH agonist. The 17-OH P response to the ACTH stimulation test after the GnRH agonist was unchanged in comparison with control tests, as well as the ratio between 17-OH P and F responses to the ACTH test. These data do not seem to confirm, as previously suggested, that high T levels of ovarian origin affect adrenal steroidogenesis.

17-alpha-Hydroxyprogesterone↗

Lyophilized type-I collagen and chronic leg ulcers.

Lyophilized type I collagen (L.C.) can stimulate wound healing by recruiting a number of different cell types (i.e. platelets and macrophages) and proteins (i.e. fibronectin). Platelets and macrophages produce locally-acting growth factors that in turn induce fibroblast and epidermal migration, angiogenesis and increase matrix synthesis. Chronic leg ulcers (C.L.U.) are the end result of microvascular failure owing to ischemia and stasis. When L.C. has been used in the treatment of C.L.U. we have observed that: a) it is significantly more effective in stimulating the healing of chronic venous ulcers when compared to hydrocolloids (p less than .05), the two products being applied upon half of the same ulcer; b) in the treatment of C.L.U. due to arterial obstruction L.C. is more effective than hydrocolloids without achieving statistical significance; c) it is very effective in the treatment of C.L.U. in thalassaemic patients; d) telethermographic studies have demonstrated an increase of blood perfusion and histological studies have shown the stimulation of angiogenesis, fibropoiesis and epidermal growth; e) the application of L.C. determines the maximum obtainable increase also under conditions of proven cicatrization difficulty; and f) enzymatic degradation of L.C. has not promoted any bacterial infection and no local or generalized sensibilization phenomena have been observed. We can conclude that L.C. is a pharmacological approach to wound healing, directly interfering with cellular and non-cellular components, and significantly improves the reparative process when delayed.

Bandages, Hydrocolloid↗

The suppressive activity of T-lymphocytes and serum factors in burned patients.

This study was performed to investigate the cell-mediated immune response in burned patients with no septic episodes. The results show that burned patients with percentage body burn higher than 20 had an impaired lymphocyte reactivity to phytohaemagglutinin and conconavalin A. This hyporesponsiveness appeared on day 3-4 and in all cases reached its maximum on day 7-8 post burn, while recovery occurred between day 11 and 29 depending on the severity of the injury. The serum from immunodepressed patients was able to inhibit the response to phytohaemagglutinin and conconavalin A of normal lymphocytes. This immunosuppressive activity was present very early after injury (on day 1-2) and before the onset of lymphocyte hyporesponsiveness to mitogens and was no longer detectable on day 7-8 post burn, when patient lymphocytes showed the greatest hyporesponsiveness to mitogens. This late depression was due to T suppressor cells.

Adolescent↗

[Anthocyanosides and the walls of the microvessels: further aspects of the mechanism of action of their protective effect in syndromes due to abnormal capillary fragility].

On the basis of previous biochemical observations, which have demonstrated the formation of complexes between anthocyanosides and some phospholipids, the AA. investigate the modifications induced by local and general administration of anthocyanosides 1) on the foreign body granuloma and 2) on the composition of the protein fractions in the exudate from the capillaries of the granulation tissue, growing on post-thromboflebitic or varicose leg ulcerations. The biochemical and histochemical data may show that the anthocyanosides protect the altered capillary walls with a double mechanism: a) increasing the endothelium barrier-effect through a stabilisation of the membrane phospholipids and b) increasing the biosynthetic processes of the acid mucopolysaccharides of the connective ground substance, by restoring the altered mucopolysaccharidic pericapillary sheat. This last effect may explain the marked increase of new-formed capillaries and collagen fibrils induced by the anthocyanosides.

Adult↗