The direct inhibition of MMP-2 and MMP-9 by an enzyme alginogel: a possible mechanism of healing support for venous leg ulcers.

Flaminal Forte is an enzyme alginogel,whose activity depends on the absorption and binding of matrix metalloproteinases (MMPs), which are known to play a crucial role in delayed wound healing. The aim of the study was to evaluate the influence of Flaminal on MMP-2/-9 activity in ulcer exudate, ex vivo. Eight patients with bilateral venous leg ulcers were treated for 4 weeks with Flaminal Forte covered by hydrocolloid ('F' wounds), or with hydrocolloid alone ('H' wounds) as a reference control. Clinical assessment did not reveal any differences between F and H wounds regarding surface reduction and general wound condition. Nevertheless, although non-significant, there was a visible difference in peri-wound skin appearance in F wounds, as compared to H wounds. The wound exudate contained high MMP-2/-9 levels, which gradually decreased as wounds healed. The attenuation of MMPs was stronger in F than in H exudate, however, in standard zymography this difference appeared non-significant. Real-time zymography revealed that Flaminal mediated a powerful direct inhibition of gelatinolytic activity of wound exudate and of recombinant MMP-2/-9 in vitro.

Comparative and developmental anatomy of cardiac lymphatics.

The role of the cardiac lymphatic system has been recently appreciated since lymphatic disturbances take part in various heart pathologies. This review presents the current knowledge about normal anatomy and structure of lymphatics and their prenatal development for a better understanding of the proper functioning of this system in relation to coronary circulation. Lymphatics of the heart consist of terminal capillaries of various diameters, capillary plexuses that drain continuously subendocardial, myocardial, and subepicardial areas, and draining (collecting) vessels that lead the lymph out of the heart. There are interspecies differences in the distribution of lymphatic capillaries, especially near the valves, as well as differences in the routes and number of draining vessels. In some species, subendocardial areas contain fewer lymphatic capillaries as compared to subepicardial parts of the heart. In all species there is at least one collector vessel draining lymph from the subepicardial plexuses and running along the anterior interventricular septum under the left auricle and further along the pulmonary trunk outside the heart and terminating in the right venous angle. The second collector assumes a different route in various species. In most mammalian species the collectors run along major branches of coronary arteries, have valves and a discontinuous layer of smooth muscle cells.

Effect of glutathione depletion on apoptosis induced by thiram in Chinese hamster fibroblasts.

Fungicide thiram, which is also known as an inducer of allergic contact dermatitis (ACD), was used as a model compound of thiuram chemicals, and its cellular effects were investigated in cultured Chinese hamster V79 cells. The level of intracellular reduced glutathione (GSH), protein sulfhydryl (PSH) groups, protein carbonyls (PC), membrane lipid peroxidation reflected by enhanced thiobarbituric acid reactive substrates (TBARS) production, as well as apoptotic effect were determined. The apoptosis induction was determined by assessing DNA fragmentation by TUNEL, annexin V binding, and caspases activation assays, using fluorescent microscope or flow cytometry, respectively. The concentrations of thiram required to induce cellular GSH depletion (by 40-50%), protein, and membrane lipid peroxidation (2-fold, and 1.7-fold, respectively), as well as to induce apoptosis in V79 Chinese hamster fibroblasts without causing necrosis through cytotoxic effects were between 50-100 microM. To investigate the role of decreased GSH content in the toxicity of thiram, GSH level was modified prior to exposure. Pretreatment of V79 cells with N-acetyl-L-cysteine (NAC), a GSH biosynthesis precursor, prevented GSH decrease, PC and TBARS production, as well as caspases activation induced by thiram exposure. On the other hand, thiram effects were enhanced by the previous depletion of cellular GSH by L-buthionine-(S,R)-sulfoximine (BSO).