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1.
Int J Mol Sci ; 25(5)2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38473910

RESUMO

Caffeine is one of the most widely consumed psychoactive drugs in the world. It easily crosses the blood-brain barrier, and caffeine-interacting adenosine and ryanodine receptors are distributed in various areas of the brain, including the hypothalamus and pituitary. Caffeine intake may have an impact on reproductive and immune function. Therefore, in the present study performed on the ewe model, we decided to investigate the effect of peripheral administration of caffeine (30 mg/kg) on the secretory activity of the hypothalamic-pituitary unit which regulates the reproductive function in females during both a physiological state and an immune/inflammatory challenge induced by lipopolysaccharide (LPS; 400 ng/kg) injection. It was found that caffeine stimulated (p < 0.01) the biosynthesis of gonadotropin-releasing hormone (GnRH) in the hypothalamus of ewe under both physiological and inflammatory conditions. Caffeine also increased (p < 0.05) luteinizing hormone (LH) secretion in ewes in a physiological state; however, a single administration of caffeine failed to completely release the LH secretion from the inhibitory influence of inflammation. This could result from the decreased expression of GnRHR in the pituitary and it may also be associated with the changes in the concentration of neurotransmitters in the median eminence (ME) where GnRH neuron terminals are located. Caffeine and LPS increased (p < 0.05) dopamine in the ME which may explain the inhibition of GnRH release. Caffeine treatment also increased (p < 0.01) cortisol release, and this stimulatory effect was particularly evident in sheep under immunological stress. Our studies suggest that caffeine affects the secretory activity of the hypothalamic-pituitary unit, although its effect appears to be partially dependent on the animal's immune status.


Assuntos
Cafeína , Hormônio Liberador de Gonadotropina , Feminino , Ovinos , Animais , Hormônio Liberador de Gonadotropina/metabolismo , Cafeína/farmacologia , Hormônio Luteinizante/metabolismo , Lipopolissacarídeos/farmacologia , Hipotálamo/metabolismo
2.
Molecules ; 28(4)2023 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-36838722

RESUMO

The growing phenomenon of honey adulteration prompts the search for simple methods to confirm the authenticity of honey. The aim of the study was to evaluate the changes in thermal characteristics, physicochemical parameters, antioxidant and enzymatic activity of honey subjected to artificial adulteration. Two series of products were prepared with the use of two different sugar syrups with an increasing dosage of adulterant (0 to 30%). After 24 months of storage, the quality of adulterated samples (partially crystallized) was assessed in comparison to the control honey (solid). Used adulteration changed physicochemical parameters and reduced antioxidant and enzymatic activity of honey (p < 0.05). The admixture of syrup and invert (p < 0.05) reduced the viscosity of liquid phase of delaminated honey in a dose-dependent manner. In the study, artificially adulterated honeys were controlled using the standard differential scanning calorimetry, DSC. In all adulterated honeys, a specific glass transition, TG, was observed in the range of 34-38.05 °C, which was not observed for control honey and pure adulterants. Moreover, the additional Tgs were observed in a wide range from -19.5 °C to 4.10 °C for honeys adulterated by syrup only. In turn, the Tg in range of 50.4-57.6 °C was observed only for the honeys adulterated by invert. These specific Tg seem to be useful to detect honey adulteration and to identify the kind of adulterant used.


Assuntos
Mel , Mel/análise , Açúcares , Antioxidantes , Contaminação de Alimentos/análise , Carboidratos
3.
Molecules ; 27(3)2022 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-35163985

RESUMO

Fir honeydew honey is a uniquely beneficial product which is often subjected to adulteration; however, pollen analysis is not useful to verify this honey type. Fourteen samples of EU protected designation of origin fir honeydew honey gathered directly from apiaries were studied. Standards of legal requirements and additional parameters, i.e., specific optical rotation, mineral content, and antioxidant activity, were tested. Five nectar honeys of different varieties were used as a comparative material. HPTLC and SDS-PAGE methods were used to fingerprint the honey types. All honeys tested fulfilled the quality requirements in terms of water content, pH, total acidity, conductivity, HMF, and diastase number. They were defined as dark amber on the Pfund scale and exhibited positive specific rotation (+2.5 to 25). Honeydew honey surpassed the tested nectar honeys in terms of mineral content and antioxidant activity as well as total polyphenolic content, except for buckwheat honey. The sugar and polyphenolic profile obtained by HPTLC allowed to distinguish honeydew from nectar honeys. The same was achieved by SDS-PAGE protein profiling. Both techniques seem to be cheap and quick tools for precisely distinguishing honeydew honey.


Assuntos
Antioxidantes/farmacologia , Mel/análise , Minerais/análise , Fenóis/análise , Quercus/química , Açúcares/análise , Antioxidantes/análise
4.
Molecules ; 27(3)2022 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-35163989

RESUMO

Nine samples of ethanolic extracts of poplar-type propolis (EEP) originated from South-Eastern Poland were analyzed in terms of the diversity of the flora around the apiary. The mineral composition, antioxidant properties, polyphenolic profile (HPTLC), and main polyphenolic constituents (HPLC-DAD) were determined. Only minor differences in chemical composition and antioxidant capacity between tested EEPs were found regardless of their botanical origin. However, the biological activity of the EEPs was more diversified. The tested EEPs showed stronger antibacterial activity against Gram-negative bacteria (Escherichia coli) compared to Gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis). Staphylococci biofilm inhibition occurred as a result of exposure to the action of four out of nine EEPs (P1-P4). Due to the various compositions of individual EEPs, a different MCF-7 cellular response was observed according to inhibition of cells migration and proliferation. Almost every sample inhibited the migration of breast cancer cells at a low concentration (0.04 µg/mL) of propolis. Even at the lowest concentration (0.02 µg/mL), each EEP inhibited the proliferation of MCF-7 cells, however, the level of inhibition varied between samples.


Assuntos
Antibacterianos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Neoplasias da Mama/tratamento farmacológico , Extratos Vegetais/farmacologia , Própole/química , Staphylococcus/efeitos dos fármacos , Movimento Celular , Proliferação de Células , Feminino , Humanos , Células MCF-7
5.
Virol J ; 17(1): 66, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32381003

RESUMO

BACKGROUND: Avian influenza virus infections cause significant economic losses on poultry farms and pose the threat of a possible pandemic outbreak. Routine vaccination of poultry against avian influenza is not recommended in Europe, however it has been ordered in some other countries, and more countries are considering use of the avian influenza vaccine as a component of their control strategy. Although a variety of such vaccines have been tested, most research has concentrated on specific antibodies and challenge experiments. METHODS: We monitored the transcriptomic response to a DNA vaccine encoding hemagglutinin from the highly pathogenic H5N1 avian influenza virus in the spleens of broiler and layer chickens. Moreover, in layer chickens the response to one and two doses of the vaccine was compared. RESULTS: All groups of birds immunized with two doses of the vaccine responded at the humoral level by producing specific anti-hemagglutinin antibodies. A response to the vaccine was also detected in the spleen transcriptomes. Differential expression of many genes encoding noncoding RNA and proteins functionally connected to the neuroendocrine-immune system was observed in different immunized groups. CONCLUSION: Broiler chickens showed a higher number and wider range of fold-changes in the transcriptional response than laying hens.


Assuntos
Anticorpos Antivirais/sangue , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/imunologia , Influenza Aviária/prevenção & controle , Vacinas de DNA/imunologia , Animais , Galinhas/genética , Galinhas/imunologia , Relação Dose-Resposta Imunológica , Perfilação da Expressão Gênica , Vacinas contra Influenza/administração & dosagem , Influenza Aviária/imunologia , Baço/imunologia , Vacinas de DNA/administração & dosagem
6.
Molecules ; 25(1)2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31878340

RESUMO

Two various species of mulberry (Morus sp.) were selected to enrich rape honey with dried leaves or lyophilized fruits (4% w/v). Finally, fruits and leaves of the 'Ukrainska' clone were introduced into the honey during creaming in concentrations from 1 to 4% w/v. The total phenolic content, antioxidant activity, anthocyanins content, and polyphenolic profile were tested in plant extracts and enriched honeys. Moreover, α-glucosidase, ß-galactosidase, and diastase activities were investigated in honeys. For mulberry extracts, chlorogenic acid isomers and rutin were considered main antioxidant compounds. The antioxidant activity of honey enriched with mulberry leaves increased even more than 50 times, due to introducing numerous phenolic acids and flavonoid glycosides. A significant decrease in the diastase activity in honey depending on the content of added mulberry leaves (almost 50% decrease in the case of 4% addition) was found, suggesting the inhibitory effect of honey with mulberry leaves against carbohydrate hydrolyzing enzymes.


Assuntos
Amilases/metabolismo , Antioxidantes/farmacologia , Frutas/química , Mel , Morus/química , Folhas de Planta/química , Polifenóis/análise , Sequestradores de Radicais Livres/química , Análise de Componente Principal
7.
Mediators Inflamm ; 2018: 5427089, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30186037

RESUMO

Prolactin is a hormone that plays an important role in the regulation of many physiological processes including lactation, reproduction, fat metabolism, and immune response. The secretion of prolactin could be disturbed by an immune stress commonly accompanying infection. This study was designed to determine the influence of bacterial endotoxin-lipopolysaccharide (LPS)-on prolactin gene (PRL) expression and prolactin release from the ovine anterior pituitary (AP) explants collected from saline- and LPS-treated ewes in the follicular phase. The expressions of toll-like receptor 4 (TLR4) and proinflammatory cytokines interleukin- (IL-) 1ß, IL-6, and tumor necrosis factor- (TNF-) α genes were also assayed. The results of the study showed that LPS stimulates prolactin secretion and IL-6 gene expression in the AP explants, but its action on lactotrophs depends on the immunological status of animal. It was demonstrated that an important role in enhancing the effect of LPS on the pituitary in the saline-treated ewes is played by LPS-binding protein (LBP)- "adapter molecule" for LPS binding to the cell surface receptor CD14 and then to TLR4. Also, it was found that bacterial endotoxin acting on the anterior pituitary cells may enhance prolactin secretion, and this effect of LPS could be mediated by IL-6 which is known as prolactin-releasing factor. Identification of the neuroendocrine and immune interactions in the regulation of prolactin secretion could be helpful in developing newer and more effective treatments for dysfunctions connected with disorders in this hormone secretion.


Assuntos
Proteínas de Fase Aguda/metabolismo , Proteínas de Transporte/metabolismo , Endotoxinas/farmacologia , Inflamação/metabolismo , Glicoproteínas de Membrana/metabolismo , Hipófise/efeitos dos fármacos , Hipófise/metabolismo , Prolactina/metabolismo , Animais , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Ovinos , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
8.
Molecules ; 23(8)2018 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-30126199

RESUMO

Honey variety is commonly defined by beekeepers based on nectar flow availability and the only laboratory method to provide verification is the melissopalynological analysis. Therefore, a quick and simple method for accurate assessment of honey variety is still being researched. The aim of the study was to evaluate the antioxidant activity of honey as an indicator of variety through the use of multivariate statistical analysis. Materials for the study consisted of 90 samples of varietal Polish honeys (rape-12, tilia-10, goldenrod-11, dandelion-5, buckwheat-6, multifloral-17, nectar-honeydew-8 and coniferous honeydew-16 and leafy honeydew-5) obtained directly from apiaries. Honeys were investigated in aspect of antioxidant capacity by photochemiluminescence (PCL) methods using standard ACW and ACL kits. As the reference FRAP and DPPH methods were used. The total phenolics content (TPC) was determined through the Folin-Ciocalteu method. The strongest antioxidant activity was found for buckwheat, while the weakest was found for rape honeys regardless of the used method. Results of the used methods were positively correlated (r = 0.42 to 0.94). Analysis conducted by PCL method confirmed that the minor fraction of honey antioxidants exhibits hydrophobic properties. Clear separation of honey varieties using PCA and Clustering method indicate that antioxidant activity can be a useful parameter for determining the botanical origin of honey.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Mel/análise , Biomarcadores , Interações Hidrofóbicas e Hidrofílicas , Fenóis/química , Fenóis/farmacologia , Polônia
9.
Phys Chem Chem Phys ; 19(22): 14337-14344, 2017 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-28537635

RESUMO

BiFeO3 (BFO) thin films were grown by chemical solution deposition on a range of electrodes to determine their role in controlling the phase formation and microstructure of the films. The crystallization on oxide electrodes followed the sequence: amorphous → Bi2O2(CO3) → perovskite, while those on Pt crystallized directly from the amorphous phase. IrO2 electrodes promoted perovskite phase formation at the lowest temperature and LaNiO3 additionally induced local epitaxial growth. All compositions exhibited fully coherent Fe-rich precipitates within the grain interior of the perovskite matrix, whereas the incoherent Bi2Fe4O9 second phase was also observed at the grain boundaries of BFO grown on Pt electrodes. The latter could be observed by X-ray diffraction as well as transmission electron microscopy (TEM) but coherent precipitates were only observed by TEM, principally evidenced by their Z contrast in annular dark field images. These data have pronounced consequences for the extended use of BFO films under an applied field for actuator, sensor and memory applications.

10.
Pharmaceuticals (Basel) ; 17(6)2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38931435

RESUMO

Ethanol extracts obtained from 13 poplar propolis samples originating from various European countries by traditional maceration were tested for total polyphenols, flavonoid content, and antioxidant activity. Moreover, the content of 18 polyphenolic compounds (from the group of phenolic acids and flavonoids) was determined using the HPLC method. The inhibitory effect of six selected extracts with the highest activity was assessed by well-diffusion method against five strains (Bifidobacterium spp., L. rhamnosus, L. acidophilus, E. coli, and Bacteroides spp.) of intestinal bacteria self-isolated from the faeces of obese probands with the use of selective media. It was found that the antioxidant activity of propolis varied depending on geographical origin and even among samples from the same region, which indicates that some other factors also influence propolis quality. The samples of different geographical origin varied mainly in the share of individual phenolic compounds, and it was not possible to find a characteristic marker of origin, excluding the galangin present in the Polish samples only. Assessing the inhibitory activity of propolis (in the range of 70 mg to 10 µg per mL) indicated that the concentration of 100 µg/mL was found as being safe for tested fecal bacteria (Bifidobacterium spp., L. rhamnosus, L. acidophilus, E. coli, and Bacteroides spp.). As no negative effect of low doses of propolis on the intestinal microflora was found, it can be suggested that its use in recommended doses brings only beneficial effects to the body.

11.
J Vet Res ; 68(3): 451-459, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39318510

RESUMO

Introduction: It is suggested that cannabinoids (CBs) may disturb reproduction through action on hypothalamic gonadotropin-releasing hormone (GnRH) neurons directly or indirectly through intermediates such as prostaglandins. The study aimed to determine the influence of intracerebroventricular (i.c.v.) injection of the endogenous cannabinoid anandamide (N-arachidonoylethanolamine - AEA), alone or with the prostaglandin synthesis inhibitor indomethacin (IND), on GnRH/luteinising hormone (LH) secretion. The purpose of the research was to clarify the role of endocannabinoids and their interaction with prostaglandins in the regulation of reproduction at the level of the hypothalamus and pituitary in anoestrous sheep. Material and Methods: The study was performed on 24 anoestrous ewes divided into four experimental groups: a control group receiving i.c.v. injection of Ringer-Locke solution, an AEA group that received i.c.v. injection of 30 µM of AEA, an IND group receiving i.c.v. injection of 5 µM of IND and an AEA + IND group that received i.c.v. injections of 30 µM of AEA and 5 µM of IND. Results: Anandamide stimulated GnRH protein and gene expression in the median eminence and protein expression in the preoptic area without influencing GnRH messenger RNA (mRNA) in this structure. Indomethacin reversed the changes in GnRH secretion after AEA administration. It was also found that AEA stimulated LH mRNA in the pituitary without influencing LH release. Conclusion: Our results support the role of endogenous cannabinoids in the regulation of reproductive processes at the central nervous system level. They may act directly on the hypothalamic GnRH neurons or indirectly through intermediates such as prostaglandins.

12.
Adv Mater ; 35(34): e2206005, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36529691

RESUMO

Zinc oxide-zinc tungstate (ZnO-ZnWO4 ) is a self-organized eutectic composite consisting of parallel ZnO thin layers (lamellae) embedded in a dielectric ZnWO4 matrix. The electromagnetic behavior of composite materials is affected not only by the properties of single constituent materials but also by their reciprocal geometrical micro-/nano-structurization, as in the case of ZnO-ZnWO4 . The light interacting with microscopic structural features in the composite material provides new optical properties, which overcome the possibilities offered by the constituent materials. Here remarkable active and passive polarization control of this composite over various wavelength ranges are shown; these properties are based on the crystal orientation of ZnO with respect to the biaxiality of the ZnWO4 matrix. In the visible range, polarization-dependent polarized luminescence occurs for blue light emitted by ZnO. Moreover, it is reported on the enhancement of the second harmonic generation of the composite with respect to its constituents, due to the phase matching condition. Finally, in the medium infrared spectral region, the composite behaves as a metamaterial with strong polarization dependence.

13.
Antioxidants (Basel) ; 10(5)2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33921973

RESUMO

Drone brood is a little-known and poorly studied bee product used and valued in the treatment of many diseases, including male infertility and women's menopausal disorders. The aim of this study was to evaluate the antioxidant activity of drone brood depending on the stage of larval development and the method of preservation. Aqueous and ethanolic homogenate extracts of drone brood were assayed for antioxidant activity (with the DPPH, FRAP, and ABTS methods), polyphenol, and flavonoid content. The extracts' polyphenolic profiles were compared by the HPTLC method. Drone brood has been shown to be more active in the earlier stages of development (between days 7-11), with a decline in antioxidant activity in the later period (by the 14th day). The freeze-drying process did not cause significant changes in the antioxidant activity of brood preparations converted to dry mass. Based on the higher activity of the aqueous compared to 70% ethanolic extracts, it was shown that the dominant fraction of brood consisted of hydrophilic antioxidants. The results obtained with different methods were highly correlated, excluding those from the ABTS assay. The HPTLC method showed that the polyphenol fraction of drone brood homogenate consisted mainly of phenolic acids and flavonoids. It was shown that drone brood has valuable antioxidant properties that can be compared with royal jelly.

14.
Animals (Basel) ; 11(2)2021 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-33673103

RESUMO

This study evaluated the effect of anandamide (AEA) on interleukin (IL)-1ß synthesis and gene expression of IL-1ß, its type I (IL-1R1) and II (IL-1R2) receptors, and IL-1 receptor antagonist (IL-1RN) in the hypothalamic structures, involved in the central control of reproduction, during inflammation. Animals were intravenously (i.v.) injected with bacterial endotoxin-lipopolysaccharide (LPS) (400 ng/kg) or saline, and two hours after LPS administration., a third group received i.v. injection of AEA (10 µg/kg). Ewes were euthanized one hour later. AEA injection (p < 0.05) suppressed LPS-induced expression of IL-1ß protein in the hypothalamus. The gene expression of IL-1ß, IL-1RN, and IL-1R2 in the hypothalamic structures was higher (p < 0.05) in animals treated with both LPS and AEA in comparison to other experimental groups. AEA administration did not influence LPS-stimulated IL-1R1 gene expression. Our study shows that AEA suppressed IL-1ß synthesis in the hypothalamus, likely affecting posttranscriptional levels of this cytokine synthesis. However, anti-inflammatory effect of AEA might also result from its stimulating action on IL-1RN and IL-1R2 gene expression. These results indicate the potential of endocannabinoids and/or their metabolites in the inhibition of inflammatory process at the level of central nervous system, and therefore their usefulness in the therapy of inflammation-induced neuroendocrine disorders.

15.
Animals (Basel) ; 10(4)2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32316539

RESUMO

Cannabinoids (CBs) are involved in the neuroendocrine control of reproductive processes by affecting GnRH and gonadotropins secretion. The presence of cannabinoid receptors (CBR) in the pituitary raises a presumption that anandamide (AEA), the endogenous cannabinoid, may act on gonadotrophic hormones secretion directly at the level of the anterior pituitary (AP). Thus, the aim of the study was to investigate the influence of AEA on gonadotropins secretions from AP explants taken from anestrous ewes. It was demonstrated that AEA inhibited GnRH stimulated luteinizing hormone (LH) and follicle stimulating hormone (FSH) secretion from the AP explants. Anandamide influences both LH and FSH gene expressions as well as their release. AEA also affected gonadoliberin receptor (GnRHR) synthesis and expression. The presence of CB1R transcript in AP explants were also demonstrated. It could be suggested that some known negative effects of cannabinoids on the hypothalamic-pituitary-gonadal axis activity may be caused by the direct action of these compounds at the pituitary level.

16.
Viruses ; 12(3)2020 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-32188100

RESUMO

Avian influenza virus (AIV) is a highly diverse and widespread poultry pathogen. Itsevolution and adaptation may be affected by multiple host and ecological factors, which are stillpoorly understood. In the present study, a turkey-origin H9N2 AIV was used as a model toinvestigate the within-host diversity of the virus in turkeys, quail and ducks in conjunction with theclinical course, shedding and seroconversion. Ten birds were inoculated oculonasally with a doseof 106 EID50 of the virus and monitored for 14 days. Virus shedding, transmission andseroconversion were evaluated, and swabs collected at selected time-points were characterized indeep sequencing to assess virus diversity. In general, the virus showed low pathogenicity for theexamined bird species, but differences in shedding patterns, seroconversion and clinical outcomewere noted. The highest heterogeneity of the virus population as measured by the number of singlenucleotide polymorphisms and Shannon entropy was found in oropharyngeal swabs from quail,followed by turkeys and ducks. This suggests a strong bottleneck was imposed on the virus duringreplication in ducks, which can be explained by its poor adaptation and stronger selection pressurein waterfowl. The high within-host virus diversity in quail with high level of respiratory sheddingand asymptomatic course of infection may contribute to our understanding of the role of quail asan intermediate host for adaptation of AIV to other species of poultry. In contrast, low viruscomplexity was observed in cloacal swabs, mainly from turkeys, showing that the within-hostdiversity may vary between different replication sites. Consequences of these observations on thevirus evolution and adaptation require further investigation.


Assuntos
Patos/virologia , Vírus da Influenza A Subtipo H9N2/patogenicidade , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Codorniz/virologia , Perus/virologia , Adaptação Biológica , Animais , Biodiversidade , Genes Virais/genética , Vírus da Influenza A Subtipo H9N2/genética , Mutação , Aves Domésticas , Virulência , Eliminação de Partículas Virais
17.
Infect Genet Evol ; 75: 103979, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31351233

RESUMO

The process of avian influenza virus (AIV) evolution in a new host was investigated in the experiment in which ten serial passages of a turkey-derived H9N2 AIV were carried out in specific pathogen free chickens (3 birds/group) inoculated by oculonasal route. Oropharyngeal swabs collected 3 days post infection were used for inoculation of birds in the next passage and subjected to analysis using deep sequencing. In total, eight mutations in the consensus sequence were found in the viral pool derived from the 10th passage: four mutations (2 in PB1 and 2 in HA) were present in the inoculum as minority variants while the other four (2 in NP, 1 in PA and 1 in HA) emerged during the passages in chickens. The detected fluctuations in the genetic heterogeneity of viral pools from consecutive passages were most likely attributed to the selective bottleneck. The genes known for bearing molecular determinants of the AIV host specificity (HA, PB2, PB1, PA) contributed most to the overall virus diversity. In some cases, a fast selection of the novel variant was noticed. For example, the amino-acid substitution N337K in the haemagglutinin (HA) cleavage site region detected in the 6th passage as low frequency variant had undergone rapid selection and became predominant in the 7th passage. Interestingly, detection of identical mutation in the field H9N2 isolates 1-year apart suggests that this substitution might provide the virus with a selective advantage. However, the role of specific mutations and their influence on the virus adaptation or fitness are mostly unknown and require further investigations.


Assuntos
Substituição de Aminoácidos , Galinhas/virologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Vírus da Influenza A Subtipo H9N2/patogenicidade , Animais , Evolução Molecular , Aptidão Genética , Vírus da Influenza A Subtipo H9N2/genética , Orofaringe/virologia , Análise de Sequência de RNA , Inoculações Seriadas , Organismos Livres de Patógenos Específicos , Perus/virologia
18.
Viruses ; 11(9)2019 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-31450681

RESUMO

Newcastle disease (ND) is responsible for significant economic losses in the poultry industry. The disease is caused by virulent strains of Avian avulavirus 1 (AAvV-1), a species within the family Paramyxoviridae. We developed a recombinant construct based on the herpesvirus of turkeys (HVT) as a vector expressing two genes: F and HN (HVT-NDV-F-HN) derived from the AAvV-1 genotype VI ("pigeon variant" of AAvV-1). This recombinant viral vaccine candidate was used to subcutaneously immunize one group of specific pathogen-free (SPF) chickens and two groups of broiler chickens (20 one-day-old birds/group). Humoral immune response was evaluated by hemagglutination-inhibition test and enzyme-linked immunosorbent assay (ELISA). The efficacy of the immunization was assessed in two separate challenge studies performed at 6 weeks of age with the use of virulent AAvV-1 strains representing heterologous genotypes IV and VII. The developed vaccine candidate elicited complete protection in SPF chickens since none of the birds became sick or died during the 2-week observation period. In the broiler groups, 90% and 100% clinical protection were achieved after challenges with AAvV-1 of IV and VII genotypes, respectively. We found no obvious relationship between antibody levels and protection assessed in broilers in the challenge study. The developed recombinant HVT-NDV-F-HN construct containing genes from a genotype VI AAvV-1 offers promising results as a potential vaccine candidate against ND in chickens.


Assuntos
Proteína HN/imunologia , Imunização/veterinária , Vírus da Doença de Newcastle , Vacinas Sintéticas/imunologia , Proteínas Virais de Fusão/imunologia , Animais , Antígenos Virais/biossíntese , Antígenos Virais/genética , Galinhas/virologia , Proteção Cruzada , Genes Virais , Proteína HN/biossíntese , Proteína HN/genética , Testes de Inibição da Hemaglutinação , Herpesvirus Meleagrídeo 1/genética , Herpesvirus Meleagrídeo 1/imunologia , Herpesvirus Meleagrídeo 1/metabolismo , Imunidade Heteróloga , Doença de Newcastle/imunologia , Doença de Newcastle/prevenção & controle , Vírus da Doença de Newcastle/genética , Vírus da Doença de Newcastle/imunologia , Doenças das Aves Domésticas/virologia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Vacinas Sintéticas/virologia , Proteínas Virais de Fusão/biossíntese , Proteínas Virais de Fusão/genética , Vacinas Virais/biossíntese , Vacinas Virais/imunologia
19.
J Vet Res ; 62(4): 447-455, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30729201

RESUMO

INTRODUCTION: Genotype VI of avian avulavirus 1 (AAvV-1) has pigeons and doves as its reservoir and is often termed pigeon paramyxovirus type-1 (PPMV-1). The pathogenesis of PPMV-1 infections in poultry is largely obscure. It is known that PPMV-1 requires a series of passages in chickens before it becomes adapted to gallinaceous poultry. MATERIAL AND METHODS: Changes in the genome of PPMV-1 were analysed after serial passages in specific pathogen free (SPF) chickens, using high-throughput sequencing. Additionally, histopathological lesions induced by PPMV-1 in experimentally inoculated pigeons, chickens, and turkeys were evaluated. RESULTS: Following six passages of PPMV-1 in chickens, 10 nonsynonymous substitutions were found including one (in the NP protein) which dominated the genetic pool of viral quasispecies. Histopathological changes induced by the post-passage PPMV-1 strain were more prominent than changes wrought by the pre-passaged PPMV-1 strain and the lesions were most intense in pigeons followed by chickens and turkeys. CONCLUSION: PPMV-1 is highly adapted to pigeons and passaging through chickens results in the acquisition of novel amino acids in the polymerase complex, which may alter the pathogenic potential of the virus.

20.
J Vet Res ; 61(4): 451-458, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29978109

RESUMO

INTRODUCTION: Due to their immunostimulatory properties TLR ligands are used prophylactically to protect against a variety of viral and bacterial pathogens in mammals. Knowledge of the molecular and functional aspects of TLRs is essential for a better understanding of the immune system and resistance to diseases in birds. For that reason, this study attempted to determine the impact of TLR21 stimulation by its synthetic ligand (CpG ODN, class B) on the chicken immune system. MATERIAL AND METHODS: Sixty embryonated chicken eggs were randomly allocated into three groups (control and two experimental groups). On day 18 of embryonic development, chickens in one experimental group were administered in ovo a low dose of CpG ODN and the birds of the second experimental group were given a high dose of the ligand. Spleens were collected at 1, 2, 5, and 10 days post-hatching (dph) for analysis of IFN-α, IFN-ß, IFN-γ, IL-6, and IL-10 expression using qRT-PCR. RESULTS: Significant differences were observed in mRNA expression levels of all the measured cytokines associated with the modulation and regulation of the immune response at different time points. CONCLUSION: The obtained data clearly demonstrate that immune response induction takes place after in ovo administration of class B CpG ODN, and that the ligand has the ability to induce cytokine responses in neonatal chicken spleen.

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