Aluminium(III) Oxide-The Silent Killer of Bacteria.

In this article, we describe the antimicrobial properties of pristine anodised aluminium oxide matrices-the material many consider biologically inert. During a typical anodisation process, chromium and chlorine compounds are used for electropolishing and the removal of the first-step aluminium oxide. Matrices without the use of those harmful compounds were also fabricated and tested for comparison. The antibacterial tests were conducted on four strains of Escherichia coli: K12, R2, R3 and R4. The properties of the matrices were also compared to the three types of antibiotics: ciprofloxacin, bleomycin and cloxacillin using the Minimal Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) tests. Moreover, DNA was isolated from the analysed bacteria which was additionally digested with formamidopyrimidine-DNA glycosylase (Fpg) protein from the group of repair glycosases. These enzymes are markers of modified oxidised bases in nucleic acids produced during oxidative stress in cells. Preliminary cellular studies, MIC and MBC tests and digestion with Fpg protein after modification of bacterial DNA suggest that these compounds may have greater potential as antibacterial agents than the aforementioned antibiotics. The described composites are highly specific for the analysed model Escherichia coli strains and may be used in the future as new substitutes for commonly used antibiotics in clinical and nosocomial infections in the progressing pandemic era. The results show much stronger antibacterial properties of the functionalised membranes on the action of bacterial membranes in comparison to the antibiotics in the Fpg digestion experiment. This is most likely due to the strong induction of oxidative stress in the cell through the breakdown of the analysed bacterial DNA.

Functionalised Anodised Aluminium Oxide as a Biocidal Agent.

In this article, we describe the antimicrobial properties of a new composite based on anodic aluminium oxide (AAO) membranes containing propyl-copper-phosphonate units arranged at a predetermined density inside the AAO channels. The samples were prepared with four concentrations of copper ions and tested as antimicrobial drug on four different strains of Escherichia coli (K12, R2, R3 and R4). For comparison, the same strains were tested with three types of antibiotics using the minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests. Moreover, DNA was isolated from the analysed bacteria which was additionally digested with formamidopyrimidine-DNA glycosylase (Fpg) protein from the group of repair glycosases. These enzymes are markers of modified oxidised bases in nucleic acids produced during oxidative stress in cells. Preliminary cellular studies, MIC and MBC tests and digestion with Fpg protein after modification of bacterial DNA suggest that these compounds may have greater potential as antibacterial agents than antibiotics such as ciprofloxacin, bleomycin and cloxacillin. The described composites are highly specific for the analysed model Escherichia coli strains and may be used in the future as new substitutes for commonly used antibiotics in clinical and nosocomial infections in the progressing pandemic era. The results show much stronger antibacterial properties of the functionalised membranes on the action of bacterial membranes in comparison to the antibiotics in the Fpg digestion experiment. This is most likely due to the strong induction of oxidative stress in the cell through the breakdown of the analysed bacterial DNA. We have also observed that the intermolecular distances between the functional units play an important role for the antimicrobial properties of the used material. Hence, we utilised the idea of the 2D solvent to tailor them.

Influence of the Zinc and Fibre Addition in the Diet on Biomechanical Bone Properties in Weaned Piglets.

The effects of the zinc and fibre source in piglets' diet on the bone mineral content, density, and strength parameters of the femur were investigated using 24 piglets fed a diet supplemented with either lignocellulose (LC) or potato fibre (PF). Half of each group of piglets consumed a diet with ZnSO4 monohydrate or with zinc glycinate (ZnGly). The diets contained similar amounts of lysine, energy, and fibre. Bone mineral content and density were over 9% higher in pigs receiving diets with ZnGly than in animals fed diets with ZnSO4. Moreover, ZnGly strongly improved maximum and elastic strength (by 25.7 and 20.0%, respectively, p < 0.0001) and bone stiffness (by 29.4%, p < 0.0001). Only the mass of the femur was affected by the type of fibre in the diet, as the femurs of piglets fed diets with LC were over 7% (p < 0.0001) heavier than in piglets fed diets with PF. The intake of digestible zinc and the zinc content in the blood serum were positively correlated with the measured bone parameters and, depending on the parameter, "r" ranged from 0.749 to 0.866 and from 0.400 to 0.479, respectively. It can be concluded that bone parameters are affected more strongly by the organic than inorganic source of zinc.

Cannabidiol and Nano-Selenium Increase Microvascularization and Reduce Degenerative Changes in Superficial Breast Muscle in C. perfringens-Infected Chickens.

Here, we demonstrated the potential of Cannabis-derived cannabidiol (CBD) and nanosized selenium (nano-Se) for the modulation of microvascularization and muscle fiber lesions in superficial breast muscle in C. perfringens-challenged chickens. The administration of CBD resulted in a decreased number of atrophic fibers (3.13 vs. 1.13/1.5 mm2) compared with the control, whereas nano-Se or both substances resulted in a decreased split fiber number (4.13 vs. 1.55/1.5 mm2) and in a lower number of necrotic myofibers (2.38 vs. 0.69/1.5 mm2) in breast muscle than the positive control. There was a significantly higher number of capillary vessels in chickens in the CBD+Nano-Se group than in the control and positive control groups (1.31 vs. 0.97 and 0.98, respectively). Feeding birds experimental diets lowered the activity of DNA damage repair enzymes, including 3,N4-ethenodeoxycytosine (by 39.6%), 1,N6-ethenodeoxyadenosine (by 37.5%), 8-oxo-guanine (by 36.2%), formamidopyrimidine (fapy)-DNA glycosylase (by 56.2%) and human alkyl adenine DNA glycosylase (by 40.2%) in the ileal mucosa, but it did not compromise the blood mitochondrial oxygen consumption rate (-2.67 OD/min on average). These findings indicate a potential link between gut mucosa condition and histopathological changes in superficial pectoral muscle under induced inflammation and show the ameliorative effect of CBD and nano-Se in this cross-talk due to their protection from mucosal DNA damage.

Effects of Fish Oil and Dietary Antioxidant Supplementation on Bone Health of Growing Lambs.

The aim of the present study was to assess the effects of partial replacement of rapeseed oil (RO) with fish oil (FO) combined with dietary supplementation of various antioxidants on the characteristics of lamb femur. Thirty male lambs were assigned to five dietary treatments and fed isoproteinous and isoenergetic diets for 35 days. The control diet was enriched with 3.0% RO, while the experimental diets were enriched either only with 2.0% RO and 1.0% FO or additionally with 0.1% carnosic acid, 0.1% carnosic acid and 0.35 ppm Se as selenized yeast, or 0.1% carnosic acid and 0.35 ppm Se as sodium selenite. After 35 days, the lambs were slaughtered, and the femur was dissected from the carcass of each animal and analyzed for morphometric, geometric, densitometric, and biomechanical properties. The dietary modifications, specifically the supplementation of FO and selenized yeast, significantly improved the geometric, densitometric, and biomechanical properties of lamb femur.

The potential of acetylsalicylic acid and vitamin E in modulating inflammatory cascades in chickens under lipopolysaccharide-induced inflammation.

Distinct enzymes, including cyclooxygenase 1 and 2 (COX-1 and COX-2), lipoxygenase (LOXs), and cytochrome P450 monooxygenase (CYP450), produce different stress mediators and mediate inflammation in birds. Bioactive agents such as acetylsalicylic acid (ASA) and vitamin E (vE) may affect enzyme activities and could be used in poultry production to control the magnitude of acute phase inflammation. Here, we characterized COX, LOX, and CYP450 mRNA expression levels in chicken immune tissues in response to Escherichia coli lipopolysaccharide (LPS) challenge and investigated whether ASA and vE could alter gene expression. Additionally, for the first time in chickens, we evaluated oxygen consumption by platelet mitochondria as a biomarker of mitochondria function in response to ASA- and vE. LPS challenge compromised bird growth rates, but neither dietary ASA nor vE significantly ameliorated this effect; however, gradually increasing dietary vE levels were more effective than basal levels. ASA regulated arachidonic acid metabolism, providing an eicosanoid synthesis substrate, whereas gradually increasing vE levels evoked aspirin resistance during challenge. Gene expression in immune tissues was highly variable, indicating a complex regulatory network controlling inflammatory pathways. However, unlike COX-1, COX-2 and CYP450 exhibited increased mRNA expression in some cases, suggesting an initiation of novel anti-inflammatory and pro-resolving signals during challenge. Measuring oxygen consumption rate, we revealed that neither the ASA nor vE levels applied here exerted toxic effects on platelet mitochondria.

Benefits and risks of iron supplementation in anemic neonatal pigs.

Iron deficiency is a common health problem. The most severe consequence of this disorder is iron deficiency anemia (IDA), which is considered the most common nutritional deficiency worldwide. Newborn piglets are an ideal model to explore the multifaceted etiology of IDA in mammals, as IDA is the most prevalent deficiency disorder throughout the early postnatal period in this species and frequently develops into a critical illness. Here, we report the very low expression of duodenal iron transporters in pigs during the first days of life. We postulate that this low expression level is why the iron demands of the piglet body are not met by iron absorption during this period. Interestingly, we found that a low level of duodenal divalent metal transporter 1 and ferroportin, two iron transporters located on the apical and basolateral membrane of duodenal absorptive enterocytes, respectively, correlates with abnormally high expression of hepcidin, despite the poor hepatic and overall iron status of these animals. Parenteral iron supplementation by a unique intramuscular administration of large amounts of iron dextran is current practice for the treatment of IDA in piglets. However, the potential toxicity of such supplemental iron implies the necessity for caution when applying this treatment. Here we demonstrate that a modified strategy for iron supplementation of newborn piglets with iron dextran improves the piglets' hematological status, attenuates the induction of hepcidin expression, and minimizes the toxicity of the administered iron.

The effect of oxidative stress on nucleotide-excision repair in colon tissue of newborn piglets.

Nucleotide-excision repair (NER) is important for the maintenance of genomic integrity and to prevent the onset of carcinogenesis. Oxidative stress was previously found to inhibit NER in vitro, and dietary antioxidants could thus protect DNA not only by reducing levels of oxidative DNA damage, but also by protecting NER against oxidative stress-induced inhibition. To obtain further insight in the relation between oxidative stress and NER activity in vivo, oxidative stress was induced in newborn piglets by means of intra-muscular injection of iron (200mg) at day 3 after birth. Indeed, injection of iron significantly increased several markers of oxidative stress, such as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) levels in colon DNA and urinary excretion of 8-oxo-7,8-dihydroguanine (8-oxoGua). In parallel, the influence of maternal supplementation with an antioxidant-enriched diet was investigated in their offspring. Supplementation resulted in reduced iron concentrations in the colon (P=0.004) at day 7 and a 40% reduction of 8-oxodG in colon DNA (P=0.044) at day 14 after birth. NER capacity in animals that did not receive antioxidants was significantly reduced to 32% at day 7 compared with the initial NER capacity on day 1 after birth. This reduction in NER capacity was less pronounced in antioxidant-supplemented piglets (69%). Overall, these data indicate that NER can be reduced by oxidative stress in vivo, which can be compensated for by antioxidant supplementation.

Lack of expression of the liver-type glutaminase (LGA) mRNA in human malignant gliomas.

In the central nervous system (CNS), liver-type glutaminase (LGA) shows a unique nuclear localization suggesting its role in the regulation of transcription rather than in the cellular glutamine metabolism. RT-PCR analysis of RNA derived from postoperative tissue samples revealed the absence or only traces of LGA mRNA in all (9) cases of malignant gliomas (astrocytoma anaplasticum, AA, WHO grade III; glioblastoma multiforme, WHO grade IV) examined. The RNA was strongly expressed in the non-neoplastic tissue derived from the same patients (6 cases), and in most of the brain metastases from different organs (5 out of 7 cases). By contrast, the mRNAs coding for the kidney-type glutaminase (KGA) and its less ubiquitous isoform GAC, which catalyze degradation of the cytoplasmic pool of Gln, were expressed in all the tissues examined. The lack of LGA may be thus considered as a useful negative diagnostic marker of highly malignant gliomas in situ.