Insulin, at physiological concentrations, enhances the polymorphonuclear leukocyte chemotactic properties.

We investigated the influence of insulin on human polymorphonuclear leukocyte (PMN) chemotaxis induced by mediators in a microchamber assay. Insulin increased, with a dose-response relationship, chemotaxis induced by formyl-methionyl-leucyl-phenylalanine, calcium ionophore and phorbol-miristyl acetate (p = 0.0057, p = 0.0001 and p = 0.0215, respectively). The hormone effect was present also at the physiological concentration of 40 microU/ml. Our data show that insulin affects PMN activity in normal subjects and therefore support the hypothesis that insulin deficiency may be responsible for the impaired PMN function observed in diabetic patients in poor metabolic control.     

Phenological and aerobiological monitoring of allergenic flora in padua (Italy). Preliminary data

A phenological study on allergenic plants was carried out in Padua during 1995 in order to identify spontaneous and cultivated allergenic species in an urban area and their distribution, and to evaluate the relationship between anthesis length and airborne pollen concentrations. In some cases, there was no temporal overlap between phenological and aerobiological data, in particular forCorylaceae, Betulaceae, Chenopodiaceae, Amaranthaceae, Polygonaceae and Fagaceae.     

Belowground community responses to fire: meta‐analysis reveals contrasting responses of soil microorganisms and mesofauna

Global fire regimes are shifting due to climate and land use changes. Understanding the responses of belowground communities to fire is key to predicting changes in the ecosystem processes they regulate. We conducted a comprehensive meta‐analysis of 1634 observations from 131 empirical studies to investigate the effect of fire on soil microorganisms and mesofauna. Fire had a strong negative effect on soil biota biomass, abundance, richness, evenness, and diversity. Fire reduced microorganism biomass and abundance by up to 96%. Bacteria were more resistant to fire than fungi. Fire reduced nematode abundance by 88% but had no significant effect on soil arthropods. Fire reduced richness, evenness and diversity of soil microorganisms and mesofauna by up to 99%. We found little evidence of temporal trends towards recovery within 10 years post‐disturbance suggesting little resilience of the soil community to fire. Interactions between biome, fire type, and depth explained few of these negative trends. Future research at the intersection of fire ecology and soil biology should aim to integrate soil community structure with the ecosystem processes they mediate under changing global fire regimes.     

Aging exacerbates negative remodeling and impairs endothelial regeneration after balloon injury

Many older patients, because of their high prevalence of coronary artery disease, are candidates for percutaneous coronary interventions (PCI), but the effects of vascular aging on restenosis after PCI are not yet well understood. Balloon injury to the right carotid artery was performed in adult and old rats. Vascular smooth muscle cell (VSMC) proliferation, apoptotic cell death, together with Akt induction, telomerase activity, p27kip1, and endothelial nitric oxide synthase (eNOS) expression was assessed in isolated arteries. Neointima hyperplasia and vascular remodeling along with endothelial cell regeneration were also measured after balloon injury. Arteries isolated from old rats exhibited a significant reduction of VSMC proliferation and an increase in apoptotic death after balloon injury when compared with adult rats. In the vascular wall of adult rats, balloon dilation induced Akt phosphorylation, and this was barely present in old rats. In arteries from old rats, Akt-modulated cell cycle check points like telomerase activity and p27kip1 expression were decreased and increased, respectively, compared with adults. After balloon injury, old rats showed a significant reduction of neointima formation and an increased vascular negative remodeling compared with adults. These results were coupled by a marked delay in endothelial regeneration in aged rats, partially mediated by a decreased eNOS expression and phosphorylation. Interestingly, chronic administration of L-arginine prevented negative remodeling and improved reendothelialization after balloon injury in aged animals. A decreased neointimal proliferation, an impaired endothelial regeneration, and an increase in vascular remodeling after balloon injury were observed in aged animals. The molecular mechanisms underlying these responses seem to be a reduced Akt and eNOS activity.     

Ragweed presence in Trieste: clinical and aerobiological data

Summary Studies on ragweed have been carried out in the province of Trieste (Northern Italy) in which it is becoming widespread. The floristic records, the increasing amount of airborne pollen monitored and the relevant skin reactivity are reported. This phenomenon, though still at the beginning, is actually showing an upward trend due to man's intervention over wider and wider areas which as a consequence become suitable for the settlement of these anthropophitic species. The aerobiological data are compared to the skin reactivities of allergic subjects.     

Degradation of [α-14C]hordenine in Hordeum vulgare plants

Evidence is presented indicating that intact plants of Hordeum vulgare degrade [α- ¹⁴C]hordenine to ¹⁴CO ₂.     

Cu(II) ion interaction with teicoplanin-vancomycin’s analog

Teicoplanin, a member of the “last chance” antibiotic family has a similar structure and the same mechanism of action as parent drug vancomycin, which is proved to be an effective binder of Cu(II) ions. However, the potentiometric and spectroscopic studies (UV-visible, CD, NMR) have shown that the modification of the N-terminal structure of the peptide backbone in teicoplanin affects considerably the binding ability towards Cu(II) ions. While vancomycin forms almost instantly the stable 3 N complex species involving the N-terminal and two amide nitrogen donors, in case of teicoplanin only two nitrogen donors derived from the N-terminal amino group and adjacent peptide bond are coordinated to Cu(II) ion within the whole pH range studied. The major factor influencing the binding mode is most likely the structure of the N-terminus of the peptide unit in the antibiotic ligand.