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The spread of antibiotic resistance among human and animal pathogens is one of the more significant public health concerns. Moreover, the restrictions on the use of particular antibiotics can limit the options for the treatment of infections in veterinary clinical practice. In this context, searching for alternative antimicrobial substances is crucial nowadays. In this study, 4,4'-dihydroxy-azobenzene (DHAB) was tested for its potential in vitro as an antimicrobial agent against two relevant human and animal pathogens, namely Staphylococcus aureus and Staphylococcus pseudintermedius . The values of minimal inhibitory concentration (MIC) were 64 and 32 mg/L respectively, and they comparable to other azo compounds of probed antimicrobial activity. In addition, the minimal bactericidal concentrations (MCB) were 256 and 64 mg/L. The mechanism by which DHAB produces toxicity in staphylococci has been investigated. DHAB caused membrane damage as revealed by the increase in thiobarbituric acid reactive substances (TBARS) such as malondialdehyde. Furthermore, differential induction of the enzymes peroxidases and superoxide dismutase in S. aureus and S. pseudintermedius suggested their prevalent role in ROS-scavenging due to the oxidative burst induced by this compound in either species. In addition, this substance was able to inhibit the formation of biofilms by both bacteria as observed by colorimetric tests and scanning electron microscopy. In order to assess the relevance of DHAB against clinical strains of MRSA, 10 clinical isolates resistant to either methicillin or daptomycin were assayed; 80% of them gave values of CMI and CMB similar to those of the control S. aureus strain. Finally, cutaneous plasters containing a composite formed by an agar base supplemented with DHAB were designed. These plasters were able to inhibit in vitro the growth of S. aureus and S. pseudintermedius , particularly the later, and this suggests that this substance could be a promising candidate as an alternative to antibiotics in the treatment of animal skin infections, as it has been proven that the toxicity of this substance is very low particularly at a dermal level.

Complexes {Ag[NHC Mes,R ]} n (R = H, 2a ; Me, 2b and 2b' ; i Pr, 2c ; i Bu, 2d ), were prepared by treatment of imidazolium precursor compounds [Im Mes,R ] (2-(3-mesityl-1 H -imidazol-3-ium-1-yl)acetate, 1a , ( S )-2- alkyl (3-mesityl-1 H -imidazol-3-ium-1-yl)acetate, 1b - d , and ( R )-2-methyl(3-mesityl-1 H -imidazol-3-ium-1-yl)acetate, 1b' , with Ag 2 O under appropriate conditions. They were characterised by analytical, spectroscopic (IR, 1 H, and 13 C NMR and polarimetry), and X-ray methods ( 2a ). In the solid state, 2a is a one-dimensional coordination polymer, in which the silver(I) cation is bonded to the carbene ligand and to the carboxylate group of a symmetry-related Ag[NHC Mes,H ] moiety. The coordination environment of the silver centre is well described by the DFT study of the dimeric model {Ag[NHC Mes,H ]} 2 . The antimicrobial properties of these complexes were evaluated versus Gram-negative bacteria E. coli and P. aeruginosa . From the observed MIC and MBC values (minimal inhibitory concentration and minimal bactericidal concentration, respectively), complex 2b' showed the best antimicrobial properties (eutomer), which were significantly better than those of its enantiomeric derivative 2b (distomer). Additionally, analysis of MIC and MBC values of 2a - d reveal a clear structure-antimicrobial effect relationship. Antimicrobial activity decreases when the steric properties of the R alkyl group in {Ag[NHC Mes,R ]} n increase.

Complexes [Ag(L R )], 2 (L R = 2,2'-(imidazolium-1,3-diyl)di(2- alkyl acetate)), were prepared by treatment of compounds HL R , 1, with Ag 2 O. They were characterised by analytical, spectroscopic (IR, 1 H and 13 C NMR and polarimetry) and X-ray methods (2c, 2c' and 2e). In the solid state, these compounds are novel one-dimensional or two-dimensional coordination polymers in which silver(I) cations are connected via the chiral [L R ] - anion with unprecedented coordination modes. The antimicrobial properties of these complexes were evaluated. 2a and 2b' showed the best antimicrobial properties (minimal inhibitory concentrations and minimal bactericidal concentration) for Pseudomonas aeruginosa and Escherichia coli pathogens. Eutomers 2b' and 2c' showed slightly better antimicrobial properties than their respective enantiomers 2b and 2c.

The unique properties that nanoparticles exhibit, due to their small size, are the principal reason for their numerous applications, but at the same time, this might be a massive menace to the environment. The number of studies that assess the possible ecotoxicity of nanomaterials has been increasing over the last decade to determine if, despite the positive aspects, they should be considered a potential health risk. To evaluate their potential toxicity, models are used in all types of organisms, from unicellular bacteria to complex animal species. In order to better understand the environmental consequences of nanotechnology, this literature review aims to describe and classify nanoparticles, evaluating their life cycle, their environmental releasing capacity and the type of impact, particularly on living beings, highlighting the need to develop more severe and detailed legislation. Due to their diversity, nanoparticles will be discussed in generic terms focusing on the impact of a great variety of them, highlighting the most interesting ones for the industry.

The complexity of some diseases-as well as the inherent toxicity of certain drugs-has led to an increasing interest in the development and optimization of drug-delivery systems. Polymeric nanoparticles stand out as a key tool to improve drug bioavailability or specific delivery at the site of action. The versatility of polymers makes them potentially ideal for fulfilling the requirements of each particular drug-delivery system. In this review, a summary of the state-of-the-art panorama of polymeric nanoparticles as drug-delivery systems has been conducted, focusing mainly on those applications in which the corresponding disease involves an important morbidity, a considerable reduction in the life quality of patients-or even a high mortality. A revision of the use of polymeric nanoparticles for ocular drug delivery, for cancer diagnosis and treatment, as well as nutraceutical delivery, was carried out, and a short discussion about future prospects of these systems is included.

Background: Alopecia areata is a T-cell mediated autoimmune disease that occurs in humans and various other mammalian species. When the disease progresses to total alopecia it is defined as alopecia areata universalis (AAU), although this outcome has only been described in humans., Hypothesis/objectives: To describe a case of canine alopecia areata universalis and its clinical outcome after 22 months of follow-up., Animal: A 9-year-old intact male cross-breed hunting dog was presented with generalized and complete noninflammatory alopecia of 12-14 months duration., Methods: Clinical examination; histopathological and immunohistochemical examination of skin biopsies., Results: There was loss of all body hair including eyelashes and vibrissae. The histopathological and immunohistochemical findings supported a diagnosis of long-standing alopecia areata. Treatment with oral ciclosporin was associated with hair regrowth but muzzle hair, most eyelashes and whiskers were still lacking after 17 months of therapy., Conclusions and Clinical Importance: To the best of the author's knowledge this is the first documented case of canine AAU. The clinical and histopathological features were consistent with a diagnosis of AAU as defined in humans. Treatment with oral ciclosporin resulted in near complete resolution of the alopecia, but after 5 months without treatment the alopecia did not relapse and spontaneous resolution cannot be ruled out., (© 2015 ESVD and ACVD.)