Study of the efficacy of Coated VICRYL Plus Antibacterial suture (coated Polyglactin 910 suture with Triclosan) in two animal models of general surgery.

OBJECTIVES: To evaluate the efficacy in vitro and in vivo of a new antibacterial suture (PGAB) compared with a traditional braided suture (PG). Our primary goals were to study microbiological effectiveness and impact on wound healing of PGAB vs PG. Secondary goal was to analyze influence on inflammatory response. METHODS: In vitro study: clinical samples of Staphylococcus epidermidis, Staphylococcus aureus, S. hominis, Staphylococcus haemolyticus, Staphylococcus auricularis, Enterococcus faecalis, Corynebacterium spp. and Escherichia coli were studied. We also implanted a flat mesh in 10 minipigs, four incisions each (two PG and two PGAB) two contaminated with S. epidermidis and two not contaminated. Finally, we performed four colic anastomosis in each of 10 minipigs, two contaminated with E. coli and two not contaminated (two PG and two PGAB). We studied the inflammatory and wound healing processes in both models. RESULTS: We observed a bactericidal efficacy of PGAB against grampositive, and bacteriostatic effect against E. coli. Mesh study: recovered CFU were lower in the group PGAB vs PG. In the group PGAB, inflammatory mediators' concentrations were lower. In the group PGAB, concentrations of wound healing mediators were normal. Colic anastomosis: recovered CFU were lower in the group PGAB vs the group PG. In the group PGAB we observed a reduction of inflammatory mediators. In the group PGAB we observed normalized concentrations of wound healing mediators. CONCLUSIONS: This study demonstrates microbiological efficacy of PGAB, that normalizes wound healing process, and an anti-inflammatory effect.

Characterization of the ask-asd operon in aminoethoxyvinylglycine-producing Streptomyces sp. NRRL 5331.

The first two genes of the threonine pathway, ask and asd, were cloned and sequenced from the aminoethoxyvinylglycine-producing Streptomyces sp. NRRL 5331. The two genes are organized in a bicistronic operon. ask, encoding the apartokinase (ASK), is located upstream from asd. The presence of a ribosome-binding site within the ask sequence suggests that this open reading frame encodes two overlapping proteins. The formation of both subunits of the aspartokinase from a single gene was studied using antibodies raised against the C-terminal end of the aspartokinase subunits. Disruption of asd results in a significant decrease of aminoethoxyvinylglycine production, thus supporting the involvement of the ask-asd operon in the biosynthesis of this metabolite. This is the first report in which a gene cluster for the first two steps of aminoethoxyvinylglycine biosynthesis is characterized.

Differences in the contents of total sugars, reducing sugars, starch and sucrose in embryogenic and non-embryogenic calli from Medicago arborea L.

The total sugars, reducing sugars, starch and sucrose in embryogenic and non-embryogenic calli from explants (cotyledons, petioles, hypocotyls and leaves) obtained from Medicago arborea L. seedlings were evaluated. Total sugars were the major components in the calli and no significant differences between embryogenic and non-embryogenic calli were observed. In contrast, important differences between the embryogenic and non-embryogenic calli were observed for reducing sugars, the highest levels being observed in embryogenic calli. The highest starch levels were found in non-embryogenic calli developed in MS medium. During the development of somatic embryogenesis very low starch levels in the callus were found. During the first months of culture, no significant differences in the sucrose content were found between calli that produced embryos and those that did not. The most important differences in sucrose were seen between calli transferred to medium F0, which had the greatest embryogenic capacity, and those transferred to medium F6, which inhibited embryogenesis. In the latter case, an increase in sucrose was observed.

The sialyl Lewis X analogue, CY-1503, down-regulates leucocyte-endothelium interactions and the inflammatory response.

OBJECTIVE: To elucidate mechanisms of protection of ischaemic liver with the sialyl Lewis X analogue CY-1503 by regulation of inflammatory mediators such as oxygen free radicals and cytokines as well as blocking the migration of leucocytes. DESIGN: Laboratory study. SETTING: Teaching hospital, Spain. ANIMALS: 122 male Sprague-Dawley rats divided into four groups: normal (n = 18), sham-operated (n = 28), ischaemic controls (n = 38), and CY-1503 (n = 38). INTERVENTIONS: Warm total hepatic ischaemia for 90 minutes followed by various periods of reperfusion. MAIN OUTCOME MEASURES: Survival, liver histology, liver function, neutrophil infiltration, and free radical and cytokine concentrations. RESULTS: 2/20 ischaemic controls survived, compared with 14/20 given CY-1503. Liver function was better, as was histological appearance judged by the Suzuki score); myeloperoxidase activity was significantly decreased (n = 6 in each group, p<0.01) as were concentrations of free radicals (n = 12 in each group, p<0.05) in the group given CY-1503. CY-1503 had no effect on concentrations of the cytokines tumour necrosis factor-alpha or interleukin 1-alpha. CONCLUSIONS: CY-1503 exerts a protective effect in that it able to down-regulate concentrations of free radicals in our rat model. It is a potent inhibitor of neutrophil migration, but has no effect on cytokine concentrations.