15 results on '"Rudyk H"'
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2. The determination of mineral density indices of the thigh bone by densitometry data in rats, for experimental fumonizinotoxycosis
- Author
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Rudyk, H. V., primary
- Published
- 2019
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3. ß-Hydroxy-ß-methylbutyrate: A feed supplement influencing performance, bone metabolism, intestinal morphology, and muscle quality of laying hens: a preliminary one-point study.
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Tomaszewska E, Świątkiewicz S, Arczewska-Włosek A, Wojtysiak D, Dobrowolski P, Domaradzki P, Puzio I, Rudyk H, Brezvyn O, and Muszyński S
- Subjects
- Animals, Female, Bone and Bones drug effects, Bone and Bones physiology, Muscle, Skeletal drug effects, Muscle, Skeletal physiology, Random Allocation, Animal Nutritional Physiological Phenomena drug effects, Chickens physiology, Valerates administration & dosage, Valerates pharmacology, Dietary Supplements analysis, Animal Feed analysis, Diet veterinary, Intestines drug effects, Intestines physiology, Intestines anatomy & histology
- Abstract
Laying hens, selectively bred for high egg production, often suffer from bone fragility and fractures, impacting their welfare and causing economic losses. Additionally, gut health and muscle quality are crucial for overall health and productivity. This study aimed to evaluate the effects of ß-Hydroxy-ß-methylbutyrate (HMB) supplementation on performance, bone metabolism, intestinal morphology, and muscle quality in laying hens. Forty-eight Bovans Brown hens were divided into a control group and an HMB-supplemented group (0.02% HMB in diet). The study spanned from the 31st to the 60th wk of age. Assessments included bone mechanical testing, serum hormonal analysis, histological analysis of bone and intestine, and muscle quality analysis. The HMB supplementation led to decreased feed intake without affecting body weight or laying rate in laying hens. It caused an increase in both mean daily and total egg weight, indicating improved feed utilization, without influencing the feed intake to egg weight ratio. Enhanced bone formation markers and altered intestinal morphometric parameters were observed, along with improved trabecular bone structure. However, no changes in measured other bone quality indices, including geometric, densitometric, or mechanical properties were observed. Muscle analysis revealed no significant changes in overall meat quality, except for a decrease in cholesterol content and alterations in the fatty acid profile, notably a reduction in total n-3 polyunsaturated and total polyunsaturated fatty acids (PUFA). In conclusion, although not all effects of HMB supplementation were unequivocally beneficial, the positive changes in performance data and trabecular bone microarchitecture support further research into various doses and durations of supplementation. Such studies are necessary to fully understand and optimize the benefits of HMB for enhancing the health and productivity of laying hens., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
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4. Yolk Fatty Acid Profile and Amino Acid Composition in Eggs from Hens Supplemented with ß-Hydroxy-ß-Methylbutyrate.
- Author
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Dajnowska A, Tomaszewska E, Świątkiewicz S, Arczewska-Włosek A, Dobrowolski P, Domaradzki P, Rudyk H, Brezvyn O, Muzyka V, Kotsyumbas I, Arciszewski MB, and Muszyński S
- Abstract
In recent years, a supplementation of livestock animals, including poultry, with β-Hydroxy-β-methylbutyrate (HMB) has gained attention for its effects on protein and fat metabolism. This study investigates the effects of HMB in the laying hen diet on egg quality, focusing on amino acid and fatty acid composition. Laying hens were supplemented with 0.02% HMB, with performance parameters and egg components analyzed. HMB supplementation led to increased albumen weight, influencing egg weight while also reducing feed intake per egg without affecting laying rate, yolk indices, fat, or cholesterol content. Notably, the study revealed significant changes in egg amino acid and fatty acid profiles due to HMB supplementation. Various amino acids, including glycine, serine, and isoleucine, were altered in the yolk, impacting nutritional value and potential health benefits. Regarding fatty acids, the study observed changes in both saturated as well as n-6 and n-3 fatty acids, affecting the overall lipid profile of egg yolks. However, the shifts in fatty acid composition could have implications for cardiovascular health due to altered ratios of n-6/n-3 fatty acids. Further research is required to comprehensively understand the implications of these findings for consumer-oriented egg quality and health benefits.
- Published
- 2023
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5. Prenatal Fumonisin Exposure Impairs Bone Development via Disturbances in the OC/Leptin and RANKL/RANK/OPG Systems in Weaned Rat Offspring.
- Author
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Tomaszewska E, Rudyk H, Muszyński S, Hułas-Stasiak M, Leszczyński N, Mielnik-Błaszczak M, Donaldson J, and Dobrowolski P
- Subjects
- Rats, Male, Female, Animals, Receptor Activator of Nuclear Factor-kappa B metabolism, Leptin, Ligands, NF-kappa B metabolism, Bone Development, RANK Ligand genetics, RANK Ligand metabolism, Osteoprotegerin genetics, Osteoprotegerin metabolism, Fumonisins toxicity
- Abstract
The goal of the current study was to examine the effects of prenatal exposure to fumonisins (FBs) on bone properties and metabolism in weaned rat offspring divided into groups intoxicated with FBs at either 0 (the 0 FB group), 60 (the 60 FB group), or 90 mg/kg b.w. 0 (the 90 FB group). Female and male offspring exposed to FBs at a dose of 60 mg/kg b.w. had heavier femora. Mechanical bone parameters changed in a sex and FBs dose-dependent manner. Growth hormone and osteoprotegerin decreased in both sexes, regardless of FBs dose. In males osteocalcin decreased, while receptor activator for nuclear factor kappa-Β ligand increased regardless of FBs dose; while in females changes were dose dependent. Leptin decreased in both male FBs-intoxicated groups, bone alkaline phosphatase decreased only in the 60 FB group. Matrix metalloproteinase-8 protein expression increased in both female FBs-intoxicated groups and decreased in male 90 FB group. Osteoprotegerin and tissue inhibitor of metalloproteinases 2 protein expression decreased in males, regardless of FBs dose, while nuclear factor kappa-Β ligand expression increased only in the 90 FB group. The disturbances in bone metabolic processes seemed to result from imbalances in the RANKL/RANK/OPG and the OC/leptin systems.
- Published
- 2023
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6. Basal Intestinal Morphology, Immunolocalization of Leptin and Ghrelin and Their Receptors in Newborn Wistar Rats after Prenatal Exposure to Fumonisins.
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Tomaszewska E, Rudyk H, Dobrowolski P, Arciszewski MB, Donaldson J, Kras K, Abramowicz B, Kuc D, and Muszyński S
- Abstract
Animal feed is very frequently contaminated with different types of mold, the metabolites of which are toxic to living organisms. Mold-contaminated cereal is rich in heat-resistant and harmful metabolites such as fumonisins (FBs). The amount of FBs consumed as part of animal feed, including livestock feed, is unknown. Therefore, this study aimed to evaluate the effects of maternal oral FB intoxication on basal duodenum morphology and the immunolocalization of gut hormones responsible for food intake (leptin and ghrelin), as well as their receptors, in newborn rat offspring. Pregnant Wistar rats were randomly allocated to one of three groups: a control group or one of two FB-intoxicated groups (60 or 90 mg FB/kg b.w., respectively). Basal morphological duodenal parameters changed in a dose- and sex-dependent manner. The intensity of the ghrelin immunoreaction was unchanged in females, while in males it increased after FB exposure (60 mg/kg b.w.), with a simultaneous decrease in expression of the ghrelin receptor. Leptin and its receptor immunoreaction intensity was decreased in both sexes following FB exposure. The current study highlighted the potential involvement of intestinal ghrelin and leptin in the metabolic disturbances observed later in life in offspring that were prenatally exposed to fumonisins.
- Published
- 2023
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7. Effect of Fermented Rapeseed Meal in Feeds for Growing Piglets on Bone Morphological Traits, Mechanical Properties, and Bone Metabolism.
- Author
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Muszyński S, Dajnowska A, Arciszewski MB, Rudyk H, Śliwa J, Krakowiak D, Piech M, Nowakowicz-Dębek B, and Czech A
- Abstract
Quality feed is essential for correct bone development and proper functioning of animals. Post-weaned piglets experience a radical change in eating behaviour that can influence their feed intake. For this reason, functional feed additives and ingredients that can be used in post-weaning feeds are needed. The objective of this study was to evaluate the effects of partially replacing wheat with rapeseed meal fermented using Bacillus subtilis strain 87Y on overall bone quality and bone metabolism in weaner piglets. From the 28th day of life, barrows were fed either a standard wheat-based diet or a diet containing 8% fermented rapeseed meal (FRSM) with or without a feed additive containing enzymes, antioxidants, probiotics, and prebiotics. The experimental period lasted 60 days, after which femur quality indices were assessed. Differences in bone length and weight were observed, but there were no changes in bone mineralization or bone mid-diaphysis morphometrical traits between treatments. FRSM inclusion reduced bone mid-diaphysis biomechanical properties, but these changes were dependent on feed-additive supplementation. Analysis of the levels of serum bone turnover markers suggests the intensification of bone resorption in FRSM-fed groups as deoxypyridinoline levels increase. The results obtained warrant further research on what the disturbances in bone mechanical properties and metabolism observed in FRSM-fed weaners means for the subsequent fattening period.
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- 2023
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8. Basal Blood Morphology, Serum Biochemistry, and the Liver and Muscle Structure of Weaned Wistar Rats Prenatally Exposed to Fumonisins.
- Author
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Tomaszewska E, Rudyk H, Wojtysiak D, Donaldson J, Muszyński S, Arciszewski MB, Lisova N, Brezvyn O, Puzio I, Abramowicz B, Pawłowska-Olszewska M, Kotsyumbas I, and Dobrowolski P
- Abstract
Cereals are often contaminated with fumonisins, which are the toxic byproducts of mold. The aim of the study was to determine the effect of maternal exposure to fumonisins on the development and the liver function of the offspring at weaning. Two doses of fumonisins (60 and 90 mg/kg b.w.) were tested. The changes in the basal blood morphology, the biochemical parameters, the absolute and relative weights of the vital organs, and the changes in the cardiac and biceps brachii muscle histology were studied. The liver damage was assessed by evaluating the liver morphology and the common clinical liver panel. Maternal fumonisin intoxication caused a decrease in the body weight at birth and an increase in the heart, liver, kidney, lungs, ovaries, and testes weights. The cytokines and hormones, as well as the red blood cell counts and hemoglobin levels, were elevated in a dose-dependent manner following the exposure to fumonisins. Maternal exposure caused degenerative morphological and structural changes in the liver, as well as inflammation in the striated muscles, such as the heart and biceps brachii, and disproportionate development of the rat offspring in a dose-dependent manner. Moreover, FB exposure resulted in the disproportional development of the rat offspring in a dose-dependent manner, which was probably caused by the bodily hormonal dysregulation. Prenatal fumonisin exposure can be a pathological precursor for serious diseases, such as obesity and diabetes, later in life.
- Published
- 2022
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9. Morphology and Chemical Coding of Rat Duodenal Enteric Neurons following Prenatal Exposure to Fumonisins.
- Author
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Kras K, Rudyk H, Muszyński S, Tomaszewska E, Dobrowolski P, Kushnir V, Muzyka V, Brezvyn O, Arciszewski MB, and Kotsyumbas I
- Abstract
Fumonisins (FBs), including fumonisin B1 and B2 produced by the fungus Fusarium verticillioides , are widespread mycotoxins contaminating crop plants as well as processed food. The aim of the experiment was to determine whether the exposure of 5-week-old pregnant rats to FBs at 60 mg/kg b.w. (group FB
60 ) or 90 mg/kg b.w. (group FB90 ) results in morphological changes in the duodenum of weaned offspring, particularly the enteric nervous system (ENS). In addition, the levels of expression of galanin and vasoactive intestinal polypeptide (VIP) in the ENS were analysed by immunofluorescence in the control and experimental groups of animals. No significant morphological changes in the thickness of the muscle layer or submucosa of the duodenum were noted in group FB60 or FB90 . In group FB90 (but not FB60 ), there was a significant increase in the width of the villi and in the density of the intestinal crypts. Immunofluorescence analysis using neuronal marker Hu C/D showed no significant changes in group FB60 or FB90 in the morphology of the duodenal ENS, i.e., the myenteric plexus (MP) and submucosal plexus (SP), in terms of the density of enteric ganglia in the MP and SP, surface area of MP and SP ganglia, length and width of MP and SP ganglia, surface area of myenteric and submucosal neurons, diameter of myenteric and submucosal neurons, density of myenteric and submucosal neurons, and number of myenteric and submucosal neurons per ganglion. In both groups, there was an increase (relative to the control) in the percentage of Hu C/D-IR/VIP-IR (IR-immunoreactive) and Hu C/D-IR/galanin-IR myenteric and submucosal neurons in the ganglia of both the MP and SP of the duodenum. In addition, in groups FB60 and FB90 , there was an increase in the number of nerve fibres showing expression of VIP and galanin in the mucosa, submucosa and circular muscle layer of the duodenum. The results indicate that prenatal exposure to FBs does not significantly alter the histological structure of the duodenum (including the ENS) in the weaned offspring. The changes observed in the chemical code of the myenteric and submucosal neurons in both experimental groups suggest harmful activity of FBs, which may translate into activation of repair mechanisms via overexpression of neuroprotective neuropeptides (VIP and galanin).- Published
- 2022
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10. The Influence of Prenatal Fumonisin Exposure on Bone Properties, as well as OPG and RANKL Expression and Immunolocalization, in Newborn Offspring Is Sex and Dose Dependent.
- Author
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Tomaszewska E, Rudyk H, Świetlicka I, Hułas-Stasiak M, Donaldson J, Arczewska M, Muszyński S, Dobrowolski P, Puzio I, Kushnir V, Brezvyn O, Muzyka V, and Kotsyumbas I
- Subjects
- Animals, Body Weight drug effects, Cancellous Bone drug effects, Cartilage, Articular metabolism, Dose-Response Relationship, Drug, Female, Male, Pregnancy, Prenatal Exposure Delayed Effects chemically induced, Rats, Sex Characteristics, Cancellous Bone metabolism, Fumonisins toxicity, Osteoprotegerin metabolism, Prenatal Exposure Delayed Effects metabolism, RANK Ligand metabolism
- Abstract
The current study examined the effects of exposure of pregnant dams to fumonisins (FBs; FB1 and FB2), from the seventh day of pregnancy to parturition, on offspring bone metabolism and properties. The rats were randomly divided into three groups intoxicated with FBs at either 0, 60, or 90 mg/kg b.w. Body weight and bone length were affected by fumonisin exposure, irrespective of sex or dose, while the negative and harmful effects of maternal FBs' exposure on bone mechanical resistance were sex and dose dependent. The immunolocalization of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-Β ligand (RANKL), in bone and articular cartilage, indicated that the observed bone effects resulted from the FB-induced alterations in bone metabolism, which were confirmed by the changes observed in the Western blot expression of OPG and RANKL. It was concluded that the negative effects of prenatal FB exposure on the general growth and morphometry of the offspring bones, as a result of the altered expression of proteins responsible for bone metabolism, were dose and sex dependent.
- Published
- 2021
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11. Trabecular Bone Parameters, TIMP-2, MMP-8, MMP-13, VEGF Expression and Immunolocalization in Bone and Cartilage in Newborn Offspring Prenatally Exposed to Fumonisins.
- Author
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Tomaszewska E, Rudyk H, Świetlicka I, Hułas-Stasiak M, Donaldson J, Arczewska M, Muszyński S, Dobrowolski P, Mielnik-Błaszczak M, Arciszewski MB, Kushnir V, Brezvyn O, Muzyka V, and Kotsyumbas I
- Subjects
- Animals, Animals, Newborn, Bone Development genetics, Cancellous Bone drug effects, Cancellous Bone growth & development, Cartilage growth & development, Cartilage metabolism, Female, Gene Expression Regulation, Developmental drug effects, Growth Plate drug effects, Oxidoreductases antagonists & inhibitors, Oxidoreductases genetics, Pregnancy, Rats, Sphingolipids biosynthesis, Fumonisins pharmacology, Matrix Metalloproteinase 13 genetics, Matrix Metalloproteinase 8 genetics, Tissue Inhibitor of Metalloproteinase-2 genetics, Vascular Endothelial Growth Factor A genetics
- Abstract
Fumonisins are protein serine/threonine phosphatase inhibitors and potent inhibitors of sphingosine N-acyltransferase (ceramide synthase) disrupting de novo sphingolipid biosynthesis. The experiment was conducted to evaluate the effects of fumonisins (FB) exposure from the 7th day of pregnancy to parturition on offspring bone development. The rats were randomly allocated to either a control group ( n = 6), not treated with FBs, or to one of the two groups intoxicated with FBs (either at 60 mg FB/kg b.w. or at 90 mg FB/kg b.w. Numerous negative, offspring sex-dependent effects of maternal FB exposure were observed with regards to the histomorphometry of trabecular bone. These effects were due to FB-inducted alterations in bone metabolism, as indicated by changes in the expression of selected proteins involved in bone development: tissue inhibitor of metalloproteinases 2 (TIMP-2), matrix metalloproteinase 8 (MMP-8), matrix metalloproteinase 13 (MMP-13), and vascular endothelial growth factor (VEGF). The immunolocalization of MMPs and TIMP-2 was performed in trabecular and compact bone, as well as articular and growth plate cartilages. Based on the results, it can be concluded that the exposure of pregnant dams to FB negatively affected the expression of certain proteins responsible for bone matrix degradation in newborns prenatally exposed to FB in a dose- and sex-dependent manner.
- Published
- 2021
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12. Changes in the Intestinal Histomorphometry, the Expression of Intestinal Tight Junction Proteins, and the Bone Structure and Liver of Pre-Laying Hens Following Oral Administration of Fumonisins for 21 Days.
- Author
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Tomaszewska E, Rudyk H, Dobrowolski P, Donaldson J, Świetlicka I, Puzio I, Kamiński D, Wiącek D, Kushnir V, Brezvyn O, Muzyka V, Doraczyńska R, Muszyński S, and Kotsyumbas I
- Subjects
- Administration, Oral, Animals, Bone and Bones pathology, Chickens, Female, Intestines chemistry, Intestines pathology, Liver pathology, Bone and Bones drug effects, Fumonisins poisoning, Intestines drug effects, Liver drug effects, Tight Junction Proteins analysis
- Abstract
Fumonisins (FB) are metabolites found in cereal grains (including maize), crop products, and pelleted feed. There is a dearth of information concerning the effects of FB intoxication on the intestinal histomorphometry, the expression of intestinal tight junction proteins, and the bone structure and liver in pre-laying hens. The current experiment was carried out on hens from the 11th to the 14th week of age. The hens were orally administered an extract containing fumonisin B1 (FB1) and fumonisin B2 (FB2) at doses of 0.0 mg/kg b.w. (body weight), 1.0 mg/kg b.w., 4.0 mg/kg b.w., and 10.9 mg/kg b.w. for 21 days. Following FB intoxication, the epithelial integrity of the duodenum and jejunum was disrupted, and dose-dependent degenerative changes were observed in liver. An increased content of immature collagen was observed in the bone tissue of FB-intoxicated birds, indicating intensified bone turnover. A similar effect was observed with regards to the articular cartilage, where enhanced fibrillogenesis was observed mainly in the group of birds that received the FB extract at a dose of 10.9 mg/kg b.w. In conclusion, FB intoxication resulted in negative structural changes in the bone tissue of the hens, which could result in worsened bone mechanics and an increase in the risk of bone fractures. Fumonisin administration, even at a dose of 1.0 mg/kg b.w., can lead to degradation of the intestinal barrier and predispose hens to intestinal disturbances later in life.
- Published
- 2021
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13. Analysis of bone osteometry, mineralization, mechanical and histomorphometrical properties of tibiotarsus in broiler chickens demonstrates a influence of dietary chickpea seeds (Cicer arietinum L.) inclusion as a primary protein source.
- Author
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Muszyński S, Tomaszewska E, Dobrowolski P, Kwiecień M, Wiącek D, Świetlicka I, Skibińska M, Szymańska-Chargot M, Orzeł J, Świetlicki M, Arczewska M, Szymanek M, Zhyla M, Hułas-Stasiak M, Rudyk H, and Tomczyk-Warunek A
- Subjects
- Animal Feed, Animal Nutritional Physiological Phenomena, Animals, Body Weight drug effects, Bone Development drug effects, Bone and Bones chemistry, Calcification, Physiologic drug effects, Chickens growth & development, Dietary Proteins administration & dosage, Dietary Proteins metabolism, Seeds chemistry, Spectroscopy, Fourier Transform Infrared, Bone and Bones metabolism, Chickens metabolism, Cicer chemistry, Diet veterinary
- Abstract
This study was focused on analyzing the effects of dietary inclusion of raw chickpea seed as a replacement of soybean meal as a primary protein source on bone structure in broiler chickens. Broiler chickens (n = 160) received in their diet either soybean meal (SBM) or raw chickpea seeds (CPS) as a primary protein source throughout the whole rearing period (n = 80 in each group). On the 42th day randomly selected chickens from each group (n = 8) were slaughtered. Collected tibiotarsus were subjected to examination of the biomechanical characteristics of bone mid-diaphysis, microstructure of the growth plate and articular cartilages; the analysis of mineral content and crystallinity of mineral phase, and the measurements of thermal stability of collagen in hyaline cartilage were also carried out. The inclusion of chickpea seeds resulted in increase of bone osteometric parameters (weight, length and mid-diaphysis cross-sectional area) and mechanical endurance (yield load, ultimate load, stiffness, Young modulus). However, when loads were adjusted to bone shape (yield and ultimate stress) both groups did not differ. Mineral density determined by means of densitometric measurements did not differ between groups, however the detailed analysis revealed the differences in the macro- and microelements composition. The results of FT-IR and XRD analyses showed no effect of diet type on mineral phase crystallinity and hydroxyapatite nanocrystallites size. In trabecular bone, the increase of real bone volume (BV/TV) and number of trabeculae was observed in the CPS group. Total thickness of articular cartilage was the same in both groups, save the transitional zone, which was thicker in the SBM group. The total thickness of the growth plate cartilage was significantly increased in the CPS group. The area of the most intense presence of proteoglycans was wider in the SBM group. The structural analysis of fibrous components of bone revealed the increase of fraction of thin, immature collagen content in articular cartilage, trabeculae and compact bone in the CPS group. The dietary inclusion of CPS affected the thermal stability of collagen, as decrease of net denaturation enthalpy was observed. This study showed a beneficial effect of CPS on the skeletal development, improving the overall bone development and the microarchitecture of cancellous bone. It suggests that CPS can be a promising replacement for SBM in broilers feeding in the aspect of animal welfare related to the development of the skeletal system., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2018
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14. In vitro cell-free conversion of bacterial recombinant PrP to PrPres as a model for conversion.
- Author
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Kirby L, Birkett CR, Rudyk H, Gilbert IH, and Hope J
- Subjects
- Animals, Cell-Free System, Cloning, Molecular, Cricetinae, Endopeptidase K pharmacology, Escherichia coli metabolism, Mice, PrPC Proteins genetics, PrPC Proteins isolation & purification, PrPSc Proteins metabolism, Protein Isoforms metabolism, Recombinant Proteins metabolism, PrPC Proteins metabolism
- Abstract
Prion diseases are associated with the conversion of the normal cellular prion protein, PrP(C), to the abnormal disease-associated protein, PrP(Sc). This conversion can be mimicked in vitro using PrP(Sc) isolated from the brains of scrapie-infected animals to induce conversion of recombinant PrP(C) into a proteinase K-resistant isoform, PrP(res). Traditionally, the 'cell-free' conversion assay has used, as substrate, recombinant PrP(C) purified from mammalian tissue culture cells or, more recently, from baculovirus-infected insect cells. The cell-free conversion assay has been modified by replacing the tissue culture-derived PrP(C) with recombinant PrP purified from bacteria. Bacterial expression and chromatographic purification give high yields of recombinant radiolabelled untagged protein, eliminates artefacts that may be due to cellular factors or antibody fragments normally present in labelled PrP preparations and allows accurate and rapid variation of protein sequence using standard molecular biological techniques. In addition, these cell-free conversion assays were carried out under more physiological conditions, giving more relevance to the assay as a model for conversion. To validate its use in this assay, this bacterial recombinant PrP has been shown to have the conversion properties of mammalian PrP(C): (i) it converts to a proteinase K-resistant isoform in the presence of PrP(Sc); (ii) the efficiency of this conversion by PrP(Sc) of different strains and species parallels that found in vivo; and (iii) its cell-free conversion is inhibited by Congo Red analogues in a structure-dependent manner similar to that seen in in vivo and in vitro cell assays.
- Published
- 2003
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15. Screening Congo Red and its analogues for their ability to prevent the formation of PrP-res in scrapie-infected cells.
- Author
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Rudyk H, Vasiljevic S, Hennion RM, Birkett CR, Hope J, and Gilbert IH
- Subjects
- Animals, Coloring Agents therapeutic use, Congo Red therapeutic use, PrPSc Proteins biosynthesis, Scrapie metabolism, Sheep, Structure-Activity Relationship, Coloring Agents chemistry, Coloring Agents pharmacology, Congo Red chemistry, Congo Red pharmacology, PrPSc Proteins antagonists & inhibitors, Scrapie prevention & control
- Abstract
Transmissible spongiform encephalopathies (TSEs) are incurable, fatal diseases. The dye Congo Red (CR) can cure cells infected with agents of the sheep TSE, scrapie, but is not used as a therapeutic or prophylactic agent in vivo, as its effects are small, possibly due to low blood-brain barrier permeability, and complicated by its intrinsic carcinogenicity. In this paper, the development is described of a structure-activity profile for CR by testing a series of analogues of this dye for their ability to inhibit the formation of the protease-resistant prion protein, PrP-res, a molecular marker for the infectious agent, in the scrapie-infected, SMB cell line. It was found that the central benzidine unit in CR, which gives the molecule potential carcinogenicity, can be replaced by other, less toxic moieties and that the sulphonate groups on the core molecule can be replaced by carboxylic acids, which should improve the brain permeability of these compounds. However, detailed dose-response curves were generated for several derivatives and they revealed that, while some compounds showed inhibition of PrP-res accumulation at high concentrations, at low concentrations they actually stimulated levels of PrP-res above control values.
- Published
- 2000
- Full Text
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