Effective antimicrobial activity of ZnO and Yb-doped ZnO nanoparticles against Staphylococcus aureus and Escherichia coli

Nanostructured Zn1-xYbxO (0.0 ≤ x ≤ 0.1) powders were prepared by the solution method using polyvinyl alcohol (PVA) and sucrose. The effect of the ytterbium doping content on the structural, morphological, optical and antimicrobial properties was analyzed. X-ray diffraction (XRD) analysis revealed that the hexagonal wurtzite structure was retained, and no secondary phases due to doping were observed. The crystallite size was under 20nm for all the Zn1-xYbxO (0.0 ≤ x ≤ 0.1) powders. The optical band gap was calculated, and the results revealed that this value increased with the ytterbium content, and the Eg values varied from 3.06 to 3.10 eV. The surface chemistry of the powders was analyzed using X-ray photoelectron spectroscopy (XPS), and the results confirmed the oxidation state of ytterbium as 3+ for all the samples. Zn1-xYbxO (0.0 ≤ x ≤ 0.1) nanoparticles were tested as antimicrobial agents against Staphylococcus aureus and Escherichia coli, resulting in a potential antimicrobial effect at most of the tested concentrations. These results were used in an artificial neural network (ANN). The results showed that it is possible to generate a model capable of forecasting the absorbance with good precision (error of 1–2%)

The Effect of Aflatoxin-B1 on Red Drum (Sciaenops ocellatus) and Assessment of Dietary Supplementation of NovaSil for the Prevention of Aflatoxicosis

Aflatoxin B1 (AFB1) is a potent carcinogen that causes growth stunting, immunosuppression and liver cancer in multiple species. The recent trend of replacing fishmeal with plant-based proteins in fish feed has amplified the AFB1 exposure risk in farm-raised fish. NovaSil (NS), a calcium montmorillonite clay, has previously been shown to reduce AFB1 bioavailability safely and efficaciously in several mammalian species. This study was designed to: (1) evaluate AFB1 impact on cultured red drum, Sciaenops ocellatus, over the course of seven weeks; and (2) assess NS supplementation as a strategy to prevent aflatoxicosis. Fish were fed diets containing 0, 0.1, 0.25, 0.5, 1, 2, 3, or 5 ppm AFB1. Two additional treatment groups were fed either 5 ppm AFB1 + 1% NS or 5 ppm AFB1 + 2% NS. Aflatoxin B1 negatively impacted red drum weight gain, survival, feed efficiency, serum lysozyme concentration, hepatosomatic index (HSI), whole-body lipid levels, liver histopathological scoring, as well as trypsin inhibition. NovaSil inclusion in AFB1-contaminated diets improved weight gain, feed efficiency, serum lysozyme concentration, muscle somatic index, and intraperitoneal fat ratios compared to AFB1-treated fish. Although not significant, NS reduced AFB1-induced histopathological changes in the liver and decreased Proliferating Cell Nuclear Antigen (PCNA) staining. Importantly, NS supplementation improved overall health of AFB1-exposed red drum

Evaluation of coastal Bermuda grass protein extract as a substitute for fishmeal in practical diets for channel catfish (Ictalurus punctatus)

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references.Issued also on microfiche from Lange Micrographics.In response to concerns over availability and cost of fishmeal for aquaculture feeds, a study was conducted to evaluate the suitability of a protein extract from coastal Bermuda grass for channel catfish (Ictalurus punctatus). The coastal Bermuda grass was treated by soaking in liquid anhydrous ammonia under high pressure at 70 C, a process known as Ammonia Fiber Explosion (AFEX), followed by alkaline extraction, isoelectric precipitation and centrifugation. Amino acid analysis of the extracted protein indicated a generally balanced profile that was first limiting in methionine. A laboratory feeding trial was conducted in which four isonitrogenous and isocaloric diets containing incremental levels of the extract were evaluated. The control diet contained 10% menhaden fishmeal and experimental diets were formulated so that the extract replaced 33, 66 and 100% of the fishmeal on an equal-protein basis. Each diet was fed to triplicate groups of channel catfish fingerlings initially weighing approximately 10 g/fish for 9 weeks. Apparent protein and organic matter digestibility of the extract also was determined utilizing chromic oxide as an inert marker. Results of the feeding trial indicated that substitution of the extract at all levels did not significantly (P>0.05) affect weight gain, feed efficiency, protein efficiency ratio, net protein utilization, intraperitoneal fat or hepatosomatic index of channel catfish. Apparent protein and organic matter digestibility coefficients of the extract were 85 and 89%, respectively. These data indicate that the extract can replace fishmeal in channel catfish diets. Further research to evaluate substitution of other ingredients with the protein extract appear warranted

PII: S0044-8486(00)00344-6

The dietary arginine requirement of channel catfish ž / Ictalurus punctatus is influenced by endogenous synthesis of arginine from glutamic acid J. Alejandro Buentello, Delbert M. Gatlin III Abstract Previous studies with young mammals have established that arginine synthesis from glutamate-derived citrulline can be a major endogenous source of arginine. Therefore, an experiment was conducted to re-assess the dietary arginine requirement of juvenile channel catfish and to determine the metabolic effects of including glutamate or glycine to maintain isonitrogenous levels among diets. Two sets of diets were formulated to contain 24 g crude proteinr100 g dry weight from caseinrgelatin and crystalline amino acids with arginine supplementation in 0.5 increments from 0.5 to 2.0 gr100 g diet. Amino acid nitrogen was maintained equal, within sets, by replacing arginine with aspartate and either glutamate or glycine. Each diet was fed to apparent satiation to triplicate groups of 12 fish initially averaging 11.4 grfish for 8 weeks. Weight gain Ž . Ž . Ž . Ž . WG , feed efficiency FE , protein efficiency ratio PER , protein retention PR and survival Ž . were significantly P -0.05 affected by arginine. At the suboptimal level of dietary arginine, glutamate appeared to contribute arginine through internally derived citrulline based on increased plasma citrulline and arginine concentrations. WG and plasma amino acid concentrations of fish fed diets with glycine suggested that it does not serve as a precursor for citrulline. Based on WG and FE, juvenile channel catfish were found to require arginine at 3.3% to 3.8% of dietary protein, when glutamate was included in the diet. The requirement estimate was 33% higher when glycine replaced glutamate in the diet and was similar to the previously determined arginine requirement of channel catfish at 4. glutamate is used for endogenous synthesis of arginine in channel catfish, especially when arginine is deficient in the diet.

Replacement of fish meal by a novel non-GM variety of soybean meal in cobia, Rachycentron canadum: Ingredient nutrient digestibility and growth performance

A constraint for the expansion of cobia aquaculture is the availability of high quality formulated diets which reduce or eliminate fish meal (FM) protein. Therefore, the nutritive value of a novel soybean cultivar, Navita™ (Navita, non-genetically modified and selectively bred soy), and regular, commodity soybean meal (SBM, de-hulled, defatted, roasted and solvent-extracted) was evaluated for cobia, Rachycentron canadum via separate digestibility and growth trials. In the first experiment Navita's apparent digestibility coefficients (ADC) were higher than those of SBM for nearly every nutrient evaluated. Crude protein ADCs were 82 and 69% for Navita and SBM, respectively. Apparent DC for amino acids ranged from 68 to 109% for Navita whereas, amino acid ADCs for SBM varied from 42 to 98%. The feeding trial utilized fish of a size that more closely resembles commercial cobia stocking (1.8kg), and was conducted over a 91-day period. Experimental diets (iso-nitrogenous and iso-energetic) were formulated such that 67% of the FM protein in the reference diet was replaced by either a combination of SBM+soy protein concentrate (SPC, Solae Profine®) labeled MXSB-diet, or by a combination of SPC+Navita; Navita-diet, hereafter. A fourth experimental diet had 80% of the FM protein replaced by a combination of Navita+SPC and was identified as Navita-high. No significant differences (P>0.05) were observed in fish fed the experimental diets for feed conversion ratio, protein efficiency ratio, feed efficiency, mean daily intake, gross protein intake, gross energy intake, visceral somatic index, muscle ratio, and hepatosomatic index. Fish fed the Navita-high diet had the lowest fish in:fish out ratio (FIFO) at 0.9±0.16. These results indicate that Navita meal can be incorporated at very high levels in the diet of marine carnivorous fish such as cobia with no detriment to performance, making it a prime candidate for FM replacement in aquafeeds.•Effects of fish meal replacement on Cobia diets were examined.•Navita's ADCs were higher than those of SBM for nearly every nutrient evaluated.•Crude protein ADCs were 82 and 69% for Navita and SBM, respectively.•Fish fed the Navita-high diet had the lowest FIFO ratio at 0.9±0.16.•Results indicate that Navita meal can be incorporated at very high levels in cobia

Can Human Oral Mucosa Stem Cells Differentiate to Corneal Epithelia?

Human oral mucosa stem cells (hOMSCs) arise from the neural crest, they can self-renew, proliferate, and differentiate to several cell lines and could represent a good source for application in tissue engineering. Because of their anatomical location, hOMSCs are easy to isolate, have multilineage differentiation capacity and express embryonic stem cells markers such as—Sox2, Oct3/4 and Nanog. We have used SHEM (supplemented hormonal epithelial medium) media and cultured hOMSCs over human amniotic membrane and determined the cell’s capacity to differentiate to an epithelial-like phenotype and to express corneal specific epithelial markers—CK3, CK12, CK19, Pan-cadherin and E-cadherin. Our results showed that hOMSCs possess the capacity to attach to the amniotic membrane and express CK3, CK19, Pan-Cadherin and E-Cadherin without induction with SHEM media and expressed CK12 or changed the expression pattern of E-Cadherin to a punctual-like feature when treated with SHEM media. The results observed in this study show that hOMSCs possess the potential to differentiate toward epithelial cells. In conclusion, our results revealed that hOMSCs readily express markers for corneal determination and could provide the ophthalmology field with a therapeutic alternative for tissue engineering to achieve corneal replacement when compared with other techniques. Nevertheless, further studies are needed to develop a predictable therapeutic alternative for cornea replacement

The Effect of Aflatoxin-B1 on Red Drum (Sciaenops ocellatus) and Assessment of Dietary Supplementation of NovaSil for the Prevention of Aflatoxicosis

Aflatoxin B(1) (AFB(1)) is a potent carcinogen that causes growth stunting, immunosuppression and liver cancer in multiple species. The recent trend of replacing fishmeal with plant-based proteins in fish feed has amplified the AFB(1) exposure risk in farm-raised fish. NovaSil (NS), a calcium montmorillonite clay, has previously been shown to reduce AFB(1) bioavailability safely and efficaciously in several mammalian species. This study was designed to: (1) evaluate AFB(1) impact on cultured red drum, Sciaenops ocellatus, over the course of seven weeks; and (2) assess NS supplementation as a strategy to prevent aflatoxicosis. Fish were fed diets containing 0, 0.1, 0.25, 0.5, 1, 2, 3, or 5 ppm AFB(1). Two additional treatment groups were fed either 5 ppm AFB(1) + 1% NS or 5 ppm AFB(1) + 2% NS. Aflatoxin B(1) negatively impacted red drum weight gain, survival, feed efficiency, serum lysozyme concentration, hepatosomatic index (HSI), whole-body lipid levels, liver histopathological scoring, as well as trypsin inhibition. NovaSil inclusion in AFB(1)-contaminated diets improved weight gain, feed efficiency, serum lysozyme concentration, muscle somatic index, and intraperitoneal fat ratios compared to AFB(1)-treated fish. Although not significant, NS reduced AFB(1)-induced histopathological changes in the liver and decreased Proliferating Cell Nuclear Antigen (PCNA) staining. Importantly, NS supplementation improved overall health of AFB(1)-exposed red drum

Human Amniotic Membrane Mesenchymal Stem Cell-Synthesized PGE₂ Exerts an Immunomodulatory Effect on Neutrophil Extracellular Trap in a PAD-4-Dependent Pathway through EP2 and EP4

Human amniotic membrane mesenchymal stem cells (hAM-MSC) secrete a myriad of components with immunosuppressive activities. In the present research, we aimed to describe the effect of prostaglandin E2 (PGE2) secreted by hAM-MSCs on neutrophil extracellular trap (NET) release and to characterize the role of its receptors (EP2/EP4) in PAD-4 and NFκB activity in neutrophils. Human peripheral blood neutrophils were ionomycin-stimulated in the presence of hAM-MSC conditioned medium (CM) treated or not with the selective PGE2 inhibitor MF-63, PGE2, EP2/EP4 agonists, and the selective PAD-4 inhibitor GSK-484. NET release, PAD-4, and NFκB activation were analyzed. Ionomycin induced NET release, which was inhibited in the presence of hAM-MSC-CM, while CM from hAM-MSCs treated with MF-63 prevented NET release inhibition. PGE2 and EP2/EP4 agonists, and GSK-484 inhibited NET release. EP2/EP4 agonists and GSK-484 inhibited H3-citrullination but did not affect PAD-4 protein expression. Finally, PGE2 and EP2/EP4 agonists and GSK-484 increased NFκB phosphorylation. Taken together, these results suggest that hAM-MSC exert their immunomodulatory activities through PGE2, inhibiting NET release in a PAD-4-dependent pathway. This research proposes a new mechanism by which hAM-MSC exert their activities when modulating the innate immune response and inhibiting NET release