Cold atmospheric plasma for surface disinfection: a promising weapon against deleterious meticillin-resistant Staphylococcus aureus biofilms.

BACKGROUND: Bacteria are becoming increasingly resistant to classical antimicrobial agents, so new approaches need to be explored. AIM: To assess the potential of cold atmospheric plasma for the management of meticillin-resistant Staphylococcus aureus (MRSA). METHODS: The 24, 48, and 72 h resistant and susceptible S. aureus biofilms were exposed to 60, 120, and 180 s treatment with plasma. FINDINGS: Increasing the treatment time results in higher cell reduction for both susceptible and resistant strains of S. aureus (P < 0.05). Up to log10 reduction factor of 5.24 cfu/cm2 can be achieved in 180 s of plasma treatment. Furthermore, plasma can substantially alter the cell's metabolisms and impact cell membrane integrity. However, it has not been shown that plasma can reduce biofilm biomass in the case of 24 h and 48 h biofilms, although the 72 h biofilm was more susceptible, and its biomass was decreased (P < 0.05). The accumulation of intrabacterial reactive oxygen species was also observed, which confirms the plasma's induction of oxidative stress. Finally, it was shown that continuous plasma exposure of bacterial cells does not cause resistance to plasma, nor is resistance developed to cefoxitin. CONCLUSION: Cold atmospheric plasma is a good candidate for S. aureus and MRSA biofilm treatment and may therefore be of value in the bacterial resistance crisis.

Phage display peptide libraries in molecular allergology: from epitope mapping to mimotope-based immunotherapy.

Identification of allergen epitopes is a key component in proper understanding of the pathogenesis of type I allergies, for understanding cross-reactivity and for the development of mimotope immunotherapeutics. Phage particles have garnered recognition in the field of molecular allergology due to their value not only in competitive immunoscreening of peptide libraries but also as immunogenic carriers of allergen mimotopes. They integrate epitope discovery technology and immunization functions into a single platform. This article provides an overview of allergen mimotopes identified through the phage display technique. We discuss the contribution of phage display peptide libraries in determining dominant B-cell epitopes of allergens, in developing mimotope immunotherapy, in understanding cross-reactivity, and in determining IgE epitope profiles of individual patients to improve diagnostics and individualize immunotherapy. We also discuss the advantages and pitfalls of the methodology used to identify and validate the mimotopes.

Ghrelin Receptor Ligands Reaching Clinical Trials: From Peptides to Peptidomimetics; from Agonists to Antagonists.

In the recent decades, great progress has been made in the development of ghrelin receptor ligands. The discovery of the first in vitro only active peptide growth hormone secretagogue derived from Met-enkephalin was the foundation for later discoveries of the receptor and the endogenous ligand ghrelin. Since then, the scope of peptides, peptidomimetics, and small-molecules targeting the ghrelin receptor, GHS-R1a, has expanded dramatically. Numerous agonists have been tested in animals and several in humans, and a handful have progressed to clinical trials for indications such as growth hormone release, gastric emptying, and cachexia. However, with the exception of the approval of GHRP-2 for diagnostic purposes in Japan, none of the candidates have been successfully introduced into the market. More recently, the attention of researchers has been concentrated on developing antagonists and inverse agonists for pharmacological treatment of the ever-expanding obese and overweight population. In this review, we describe the development of GHS-R1a targeting agonists, antagonists, and inverse agonists. We focus on current and completed clinical trials and the therapeutic potential of currently available ligands.

Peptides binding to the hunger hormone ghrelin.

The neutralisation of circulating ghrelin, the only known peripheral orexigenic peptide hormone, is a promising approach for the pharmacological treatment of obesity. To select peptides with an affinity towards ghrelin, 4 selection procedures were carried out with random peptide phage display libraries Ph.D.-7 and Ph.D.-12. Due to the absence of a common consensus motif, a stepwise elimination approach was used. The pool of selected peptides displaying phage clones was thoroughly examined to remove any potential target-unrelated peptides. The affinity of the remaining phage clones for ghrelin was tested with ELISA. An analysis of the binding properties revealed four-phage displayed peptides that bind to ghrelin with moderate affinity, with ADTVPRH and MEMKKTHPVLGA being the most specific. Additional advantage of peptide MEMKKTHPVLGA is an indication of binding to octanoyl group on N-terminal part of ghrelin, involved in receptor interaction. Hence peptide MEMKKTHPVLGA represents the most suitable lead for further investigation.

The endothelial plasma membrane transporter bilitranslocase mediates rat aortic vasodilation induced by anthocyanins.

BACKGROUND AND AIMS: Anthocyanins, a sub-class of flavonoids, induce endothelium-dependent vasorelaxation, by activating endothelial nitric oxide synthase and consequently increasing production of the vasorelaxant agent nitric oxide. It is not yet clear if anthocyanin-induced vasorelaxation starts with their interaction with plasma membrane receptors in the extracellular compartment, or with their membrane transport toward intracellular molecular targets. We therefore investigated the possible role of bilitranslocase (TC 2.A.65.1.1), an endothelial plasma membrane carrier that transports flavonoids, in the vasodilation activity induced by anthocyanins. METHODS AND RESULTS: Vascular reactivity was assessed in thoracic aortic rings obtained from male Wistar rats. Pre-treatment of aortic rings with anti-sequence bilitranslocase antibodies targeting the carrier, decreased vasodilation induced by cyanidin 3-glucoside and bilberry anthocyanins. CONCLUSION: Here we show for the first time that bilitranslocase mediates a critical step in vasodilation induced by anthocyanins. This offers new insights into the molecular mechanism involved in endothelium-dependent vasorelaxation by flavonoids, and the importance of their specific membrane carriers.

Peptide inhibitor of pancreatic lipase selected by phage display using different elution strategies.

Interference with fat hydrolysis results in the reduced use of ingested lipids. Inhibition of pancreatic lipase reduces the efficiency of fat absorption in the small intestine and thereby initiates modest long-term reduction in body weight. In an attempt to select peptides with affinity for the surface of pancreatic lipase and potential inhibitory activity, a random, cyclic heptapeptide phage-displayed library was used. Five independent selections, differing in elution step, were performed. In three selection protocols, a sequential elution strategy was applied in anticipation of improving the selection of high-affinity clones. Four heptapeptides with the highest affinity, seemingly for pancreatic lipase, were selected, synthesized, and characterized for their capacity to inhibit enzyme function. Although no clear consensus among the sequenced peptides was found, one of the selected peptides inhibited pancreatic lipase with an apparent inhibition constant of 16 muM.

Lack of efficacy of 6-week treatment with oral terbinafine for tinea capitis due to Microsporum canis in children.

Twenty-two children aged 2 to 9 years with noninflammatory tinea capitis due to Microsporum canis were evaluated in an open clinical pilot study run from January 1994 to July 1995. Each child was given oral terbinafine according to body weight for 6 weeks. Mycologic evaluation was done at the end of treatment and after follow-up periods of 4 and 8 weeks. None of the patients achieved complete mycologic cure by the end of the treatment period. Four weeks later complete mycologic cure was established in nine patients, and on final evaluation in seven. The treatment was very well tolerated by all the children. No systemic adverse effects were noted. According to our data, a 6-week course of oral terbinafine is inadequate for tinea capitis due to M. canis in children. Further study is needed to determine the most appropriate duration of therapy.

Is Microsporum canis infection about to become a serious dermatological problem?

In Europe, especially in the Mediterranean, the incidence of Microsporum canis infection has been on a steep increase during the recent years. In some countries (Italy) and geographic areas (Slovenia), M. canis is the most often isolated dermatophyte. In Slovenia (Yugoslavia), a dramatic increase in the incidence of M. canis infection has been observed recently, both in absolute figures and as compared to the rest of isolated dermatophytes. M. canis is a cause of tinea most prevalent in children. All attempts made during the past 6 years to eliminate the natural source of infection, represented mainly by stray cats, have failed. M. canis infection is becoming a serious epidemiologic problem in Europe. For its solution, integrated efforts of medical and veterinary services, and probably more stringent rules and controls in this particular area, will be required.

Additive effect of the combination of griseofulvin and ketoconazole against Microsporum canis in vitro.

The susceptibility of 28 strains of Microsporum canis to griseofulvin, to ketoconazole and to a combination of both antifungal drugs was determined. Griseofulvin proved to be more active than ketoconazole. The combination of both antifungal agents was found to exert an additive effect.

Variable incidence of nickel dermatitis.

The incidence of nickel sensitivity in Ljubljana, Yugoslavia, was stable in the periods 1972-1976 (6.7%) and 1977-1981 (6.3%). An increase became apparent when the incidence rose to 8.0% in 1982, and 9.1% in 1982-1986. The sex ratio in 1972-1976 was 2:1 with a female predominance, doubling to 4:1 in 1977-1981 and doubling again to 9:1 in 1982-1986. The highest incidence was in the age groups of 11-20 and 21-30 years. Nickel remains a rare cause of occupational dermatitis. Cheap metal jewelry is the likely source of the increased incidence.

Thermodynamics of the isothermal interaction of beta-lactoglobulin with guanidinium chloride and urea.

A thermodynamic study of the isothermal interaction of beta-lactoglobulin with guanidinium chloride and urea has been performed. Enthalpies of interaction of the two denaturants have been obtained by calorimetric measurements, and the free energy of interaction calculated from previously determined preferential binding of denaturants. In separate dilatometric experiments the volume changes accompanying the interaction of guanidinium chloride with beta-lactoglobulin have also been determined.