Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
1.
Materials (Basel) ; 15(24)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36556786

RESUMO

The magnesium-aluminium alloy AZ91 was inoculated with zirconium to refine the microstructure. Six different concentrations of zirconium content were tested, ranging from 0.1 to 0.6 wt %, and compared to the baseline AZ91 alloy without modification. Melted metal was poured into a preheated ceramic mould and the temperature was measured and recorded during the solidification. The derivative and thermal analysis (DTA) was performed to compare the crystallisation dynamics. Formed microstructure was analysed using an optical microscope, scanning electron microscopy (SEM-EDX) and energy dispersive X-ray spectrometry (XRD). The chemical composition was measured using an arc spectrometer. The time of solidification was shortened for the samples with a concentration of zirconium 0.3 wt % and the microstructure was refined. The level of grain refinement remained below 10% and the grain shape was changed to more spherical shapes. Both the primary magnesium and eutectic phases were modified. However, at a low concentration of zirconium (0.1 and 0.2 wt %), the primary grain size was increased. Therefore, the optimal zirconium concentration was 0.3 wt %. Larger concentrations (0.4 to 0.6 wt %) did not provide any additional benefit. Theoretical analysis showed that some Al3Zr intermetallic phases can form, which was confirmed on the derivate curve of the thermal analysis, and SEM-EDS and XRD analyses.

2.
Methods Mol Biol ; 2538: 189-205, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35951301

RESUMO

Bacterial functional amyloids, apart from their many other functions, can influence the resistance of bacteria to antibiotics and other antibacterial agents. Mechanisms of modulation of susceptibility of bacterial cells to antimicrobials can be either indirect or direct. The former mechanisms are exemplified by the contribution of functional amyloids to biofilm formation, which may effectively prevent the penetration of various compounds into bacterial cells. The direct mechanisms include the effects of bacterial proteins revealing amyloid-like structures, like the C-terminal region of the Escherichia coli Hfq protein, on the expression of genes involved in antibiotic resistance. Therefore, in this paper, we describe methods by which effects and mechanisms of action of bacterial amyloids on antibiotic resistance can be studied. Assessment of formation of biofilms, determination of the efficiency of antibiotic resistance in solid and liquid media, and determination of the effects on gene expression at levels of mRNA abundance and stability and protein abundance are described.


Assuntos
Biofilmes , Escherichia coli , Amiloide/metabolismo , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana/genética , Resistência Microbiana a Medicamentos , Escherichia coli/metabolismo
3.
QRB Discov ; 3: e15, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37529279

RESUMO

Interactions between proteins and single-stranded DNA (ssDNA) are crucial for many fundamental biological processes, including DNA replication and genetic recombination. Thus, understanding detailed mechanisms of these interactions is necessary to uncover regulatory rules occurring in all living cells. The RNA-binding Hfq is a pleiotropic bacterial regulator that mediates many aspects of nucleic acid metabolism. The protein notably mediates mRNA stability and translation efficiency by using stress-related small regulatory RNA as cofactors. In addition, Hfq helps to compact double-stranded DNA. In this paper, we focused on the action of Hfq on ssDNA. A combination of experimental methodologies, including spectroscopy and molecular imaging, has been used to probe the interactions of Hfq and its amyloid C-terminal region with ssDNA. Our analysis revealed that Hfq binds to ssDNA. Moreover, we demonstrate for the first time that Hfq drastically changes the structure and helical parameters of ssDNA, mainly due to its C-terminal amyloid-like domain. The formation of the nucleoprotein complexes between Hfq and ssDNA unveils important implications for DNA replication and recombination.

4.
Int J Mol Sci ; 22(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34445592

RESUMO

The Hfq protein is a bacterial RNA chaperone, involved in many molecular interactions, including control of actions of various small RNA regulatory molecules. We found that the presence of Hfq was required for survival of plasmid-containing Escherichia coli cells against high concentrations of chloramphenicol (plasmid p27cmr), tetracycline (pSC101, pBR322) and ampicillin (pBR322), as hfq+ strains were more resistant to these antibiotics than the hfq-null mutant. In striking contrast, production of Hfq resulted in low resistance to high concentrations of kanamycin when the antibiotic-resistance marker was chromosome-borne, with deletion of hfq resulting in increasing bacterial survival. These results were observed both in solid and liquid medium, suggesting that antibiotic resistance is an intrinsic feature of these strains rather than a consequence of adaptation. Despite its major role as RNA chaperone, which also affects mRNA stability, Hfq was not found to significantly affect kan and tet mRNAs turnover. Nevertheless, kan mRNA steady-state levels were higher in the hfq-null mutant compared to the hfq+ strain, suggesting that Hfq can act as a repressor of kan expression.This observation does correlate with the enhanced resistance to high levels of kanamycin observed in the hfq-null mutant. Furthermore, dependency on Hfq for resistance to high doses of tetracycline was found to depend on plasmid copy number, which was only observed when the resistance marker was expressed from a low copy plasmid (pSC101) but not from a medium copy plasmid (pBR322). This suggests that Hfq may influence survival against high doses of antibiotics through mechanisms that remain to be determined. Studies with pBR322Δrom may also suggest an interplay between Hfq and Rom in the regulation of ColE1-like plasmid replication. Results of experiments with a mutant devoid of the part of the hfq gene coding for the C-terminal region of Hfq suggested that this region, as well as the N-terminal region, may be involved in the regulation of expression of antibiotic resistance in E. coli independently.


Assuntos
Antibacterianos/farmacologia , Cromossomos Bacterianos/genética , Resistência Microbiana a Medicamentos/genética , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Fator Proteico 1 do Hospedeiro/genética , Mutação , Plasmídeos/genética , Escherichia coli/efeitos dos fármacos
5.
Acta Vet Scand ; 62(1): 44, 2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32787889

RESUMO

BACKGROUND: The Sydney system for assessing inflammatory lesions in the gastric mucosa is based on endoscopic and histological examinations. This study aimed to apply the Sydney system to diagnose gastritis in dogs. The study also compared the results of endoscopic and histological examinations conducted on gastric mucosal biopsy specimens. A total of 56 dogs with chronic vomiting were analyzed in the study. The physical appearance of the gastric mucosa was assessed through endoscopic examination, while the severity of the gastric inflammation, inflammation activity, glandular atrophy, and intestinal metaplasia were assessed by histopathological examination. RESULTS: The endoscopic examination confirmed the presence of inflammatory lesions affecting the gastric corpus and pylorus in all the dogs, although the severity of these lesions differed between the individuals. Reflux gastritis was the most commonly observed gastric inflammation. In the histopathological examination of the gastric mucosal samples, inflammatory lesions were found in the gastric corpus of 53 dogs, while 55 dogs had lesions in the pylorus. This corresponds to a 96.4% agreement between the methods. CONCLUSIONS: The Sydney system is a useful tool for macroscopic and microscopic assessment of changes in the gastric mucosa as it enables the determination of inflammation type and severity, which helps the canine gastroenterologists to reliably compare the results of the tests performed in different facilities. Besides, the use of the Sydney system in diagnosing lesions facilitates the selection and effective monitoring of treatment. However, despite a high rate of agreement between the results of endoscopic and histopathological examinations, it is recommended to use both these methods for the assessment of the gastric mucosa in dogs.


Assuntos
Doenças do Cão/diagnóstico , Mucosa Gástrica/patologia , Gastrite/veterinária , Animais , Doença Crônica/veterinária , Doenças do Cão/patologia , Cães , Endoscopia/veterinária , Feminino , Gastrite/diagnóstico , Gastrite/patologia , Masculino , Polônia , Estudos Retrospectivos
6.
Toxins (Basel) ; 12(6)2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32545232

RESUMO

An increasing number of studies have found that modified mycotoxins, such as free mycotoxins, naturally occur in food, and severely impact food safety. The present study investigated concentrations of trichothecenes nivalenol (NIV), deoxynivalenol (DON), and zearalenone (ZEN), together with their modified forms, nivalenol-3-glucoside (NIV-3G), deoxynivalenol-3-glucoside (DON-3G), and zearalenone-14-glucoside (ZEN-14G) and zearalenone-14-sulfate (ZEN-14S), respectively, at successive stages of malt loaf production (flour, dough kneading/fermentation, loaf baking). Toxins in bakery products originate in flour produced from wheat grain that is naturally contaminated with Fusarium culmorum. Mycotoxin concentrations were determined using high-performance liquid chromatography-high resolution mass spectrometry, and did not significantly change during the successive stages of bread production. After the dough kneading/fermentation stage, concentrations of NIV-3G and DON-3G were slightly increased, whereas those of ZEN and ZEN-14S were slightly decreased. The largest average decrease (21%) was found in ZEN-14G. After the baking stage, the average concentrations of NIV-3G, DON-3G, ZEN-14S, and ZEN-14G in the loaf crumb and crust decreased by 23%, 28%, 27%, and 20%, respectively, compared with those in the dough. During this technical process, the concentration of ZEN-14G in loaf crumb significantly decreased by an average of 48%, and those of ZEN, ZEN-14S, and ZEN-14G in loaf crust decreased by an average of 29%, 42%, and 48%, respectively. Considering the possibility of modified mycotoxins degradation to free forms, as well as the ability to synthesize them from free forms during technological processes, it would be prudent to consider them together during analysis.


Assuntos
Pão/microbiologia , Grão Comestível/microbiologia , Farinha/microbiologia , Microbiologia de Alimentos , Fusarium/metabolismo , Micotoxinas/metabolismo , Triticum/microbiologia , Biotransformação , Culinária , Fermentação , Temperatura Alta
7.
BMC Vet Res ; 15(1): 293, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31412920

RESUMO

BACKGROUND: Magnetic resonance imaging using gadoxetic acid, a hepatocyte-specific contrast agent, is one of the most useful MRI techniques used to diagnose liver tumours in humans. During the hepato-biliary phase, there is uptake of gadoxetic acid by normal hepatocytes, leading to hepatic parenchymal enhancement. This feature is used in human medicine to diagnose hepatic parenchymal metastatic disease, to differentiate primary liver tumours, to diagnose liver cirrhosis and focal nodular hyperplasia. This study presents the preliminary results of magnetic resonance imaging of focal lesions localised in the liver parenchyma in dogs following the administration of gadoxetic acid. RESULTS: The lesion enhancement ratio (ERlesion) in the tumour metastasis was 0.05; the liver enhancement ratio (ERliver) - 0.49 and the post-contrast lesion-to-liver contrast ratio (CR) was 0.17. In dogs with hepatocellular hyperplasia, these values were 0.54; 0.51; and 1.18, respectively. In two dogs with a hepatic adenoma, the ERlesion was 0.26 and 0.17, respectively; the ERliver was 0.47 and 0.47, respectively and the CR was 0.33 and 0.31, respectively. In the dog with a neuroendocrine tumour, the ERlesion was 0.03; the ERliver amounted to 0.58 and the CR was 0.35. In the case of a hepatocellular carcinoma, these coefficients were 0.2, 0.6 and 0.3, respectively. CONCLUSION: Based on the results, it may be assumed that the MR images of the proliferative hepatic parenchymal lesions in dogs using gadoxetic acid are similar to those obtained in humans. This suggests that the contrast enhancement patterns used in human medicine may be useful in differentiating hepatic parenchymal lesions in dogs.


Assuntos
Meios de Contraste/farmacologia , Doenças do Cão/diagnóstico por imagem , Gadolínio DTPA/farmacologia , Neoplasias Hepáticas/veterinária , Imageamento por Ressonância Magnética/veterinária , Animais , Cães , Feminino , Neoplasias Hepáticas/diagnóstico por imagem , Masculino , Projetos Piloto
8.
Langmuir ; 35(29): 9564-9571, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31287703

RESUMO

The control of droplets deposited onto textured surfaces is of great importance for both engineering and medical applications. This research investigates the dynamics of a single droplet deposited into a confined space and its final equilibrium morphology, with emphasis given to droplet deposition under print head misalignment, the effect of nonuniform wettability, and deposition of droplets with varying sizes. A multiphase pseudopotential lattice Boltzmann methodology is used to simulate the process of deposition. The print quality is characterized in terms of a parameter referred to as the wetted fraction, which describes the proportion of the cavity that is wetted by the droplet. Our results show how single and multiple axis misalignment affect the final equilibrium morphology, and it was found for comparable configurations that multiaxis misalignment resulted in a higher wetted fraction. Investigations into wettabilities of the substrate and cavity wall revealed how larger ratios of the contact angles between the two enhance the ability for the droplet to self-align within the cavity. Additionally, a range of uniform wettabilities between the substrate and cavity were found, which mitigate against misalignment. Investigations into varying droplet sizes relative to the cavity revealed how misalignment can be compensated for with larger droplets, and limits for filling a cavity with a single drop are defined. Finally, we explore the deposition with misalignment into closely positioned cavities where it is found that the spacing between cavities is a key factor in determining the maximum permissible misalignment.

9.
Acta Vet Scand ; 61(1): 27, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31196125

RESUMO

The aim of this study was to describe a core needle biopsy technique in the guinea pig (Cavia porcellus) and to assess the incidence of complications when applying this method. Biopsies were taken from the right hepatic lobe of 36 healthy guinea pigs under ultrasound guidance using a Tru-Cut needle. There were no immediate complications in 35 animals but ultrasound images showed a haemorrhage from the biopsy site in one guinea pig. The haemorrhage stopped after administering a sterile cooling dressing. One guinea pig died 13 days after the biopsy due to late complications. The procedure is in some animals associated with severe, potential life-threatening, complications. Assessment of the biopsy site by ultrasonography for 30 min after the procedure is recommended to allow timely handling of haemorrhage. The procedure is not recommended in animals with a suspected coagulopathy. Due to the risk of severe complications, this procedure should be restricted to guinea pigs where the result of the biopsy examination is expected to be valuable for the choice of treatment or prognosis. Owners should be made aware of the risks associated with the procedure.


Assuntos
Biópsia com Agulha de Grande Calibre/veterinária , Cobaias , Fígado/cirurgia , Medicina Veterinária/métodos , Animais , Biópsia com Agulha de Grande Calibre/efeitos adversos , Biópsia com Agulha de Grande Calibre/normas , Hemorragia/etiologia , Hemorragia/veterinária , Ultrassonografia
10.
Materials (Basel) ; 12(6)2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30901818

RESUMO

The technique of flattening the temperature profile and controlling the formation of both the dendritic microstructure and grain structure in the directional solidification of nickel-based superalloy casting, using the novel inner radiation baffles (IRBs) in the Bridgman process, is presented in this paper. These baffles matched to the shape of mold and were placed horizontally along its height at various distances from the casting base. The plate castings of CMSX-4 superalloy were fabricated without and with the use of IRBs, withdrawing the mold at the rate of 6 mm/min from the heating to the cooling area of the industrial Bridgman furnace. Thermal analysis of the directional solidification of castings was carried out using the ProCAST software for a process where the various designs of the radiation baffle were applied. The results of the solidification conditions, the shape of liquidus and solidus isotherms, and grain structure obtained for the IRBs were compared with those reached for the standard ring-shaped (AERB) or perfectly adjusted (PARB) radiation baffles. The use of IRB resulted in flattening of the temperature distribution and decrease of the curvature of liquidus and solidus isotherms, as well as an increase of temperature gradient and cooling rate, compared with the process where AERB was only used. Consequently, primary dendrite arm spacing (PDAS) reached similar values across the width of casting and equaled to approximately 370 µm, reducing its average value by 26%, compared with the standard process. The change in predicted axial temperature gradient in casting was not found when thermophysical properties of molybdenum IRBs were used. The increase in graphite IRBs number in mold from seven to 14 caused the reduction of inhomogeneity of axial temperature gradient along the casting height.

11.
J Microbiol Methods ; 154: 141-146, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30393029

RESUMO

The study describes a novel diagnostic protocol based on a loop-mediated isothermal DNA amplification (LAMP) for identification of wheat grains infection by Tilletia laevis, Tilletia caries (common bunt) and Tilletia controversa (draft bunt). The presented data showed that the LAMP analysis is a simple, specific and rapid method that could be used for detection of Tilletia spp. in contaminated grain samples. The lowest DNA concentration required for the successful detection of Tilletia spp. strains were estimated to be 0.001 ng/µl. Simultaneously the detection limit for wheat grain contamination by T. caries and T. laevis teliospores was estimated at 20 µg per 100 g of grain. For T. controversa detection limit was lower and was approximately 20 mg of teliospores per 100 g of grain. The negative results of the LAMP reactions were achieved for the most common fungal species colonizing wheat grain like Fusarium spp., Alternaria sp., Cladosporium sp., Helminthosporium sp., and Penicillium sp.


Assuntos
Basidiomycota/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico/métodos , Doenças das Plantas/microbiologia , Triticum/microbiologia , Grãos Integrais/microbiologia , Basidiomycota/classificação , Basidiomycota/genética , DNA Fúngico/análise , DNA Fúngico/isolamento & purificação , Microbiologia de Alimentos/métodos , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Limite de Detecção , Sementes/microbiologia , Sensibilidade e Especificidade , Análise de Sequência de DNA , Especificidade da Espécie , Triticum/genética
12.
Cell Mol Bioeng ; 10(6): 549-562, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29151982

RESUMO

INTRODUCTION: In the current study, we investigated the effect of low magnitude, low frequency (LMLF) mechanical vibrations on the osteogenic differentiation potential of human adipose derived mesenchymal stem cells (hASC), taken from elderly patients. METHODS: During 21 days in osteogenic culture medium, cells were periodically exposed to three different frequencies (25, 35 and 45 Hz) of continuous sinusoidal oscillation, using a vibration generator. We measured cell proliferation, cell morphology, calcium and phosphorus deposition using Almar Blue assay, fluorescence microscopy, scanning electron microscopy, and a EDX detector, respectively. Osteogenic differentiation was measured by assessing protein and mRNA levels. Osteogenesis was confirmed by detection of specific markers with alkaline phosphatase and enzyme-linked immunosorbent assays for: bone morphogenetic protein 2 (BMP-2), osteocalcin (OCL) and osteopontin (OPN). RESULTS: We found that 25 Hz vibrations had the greatest impact on hASC morphology, ultrastructure, and proliferation. We observed the formation of osteocyte- and hydroxyapatite-like structures, an increased quantity of calcium and phosphorus deposits, and increased differentiation in the stimulated groups. CONCLUSIONS: Our findings suggest that LMLF vibrations could be used to enhance cell-based therapies for treatment of bone deficits, particularly in elderly patients, where the need is greatest.

13.
Nucleic Acids Res ; 45(12): 7299-7308, 2017 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-28521053

RESUMO

Hfq is a bacterial protein that is involved in several aspects of nucleic acids metabolism. It has been described as one of the nucleoid associated proteins shaping the bacterial chromosome, although it is better known to influence translation and turnover of cellular RNAs. Here, we explore the role of Escherichia coli Hfq's C-terminal domain in the compaction of double stranded DNA. Various experimental methodologies, including fluorescence microscopy imaging of single DNA molecules confined inside nanofluidic channels, atomic force microscopy, isothermal titration microcalorimetry and electrophoretic mobility assays have been used to follow the assembly of the C-terminal and N-terminal regions of Hfq on DNA. Results highlight the role of Hfq's C-terminal arms in DNA binding, change in mechanical properties of the double helix and compaction of DNA into a condensed form. The propensity for bridging and compaction of DNA by the C-terminal domain might be related to aggregation of bound protein and may have implications for protein binding related gene regulation.


Assuntos
DNA Bacteriano/ultraestrutura , DNA/ultraestrutura , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Fator Proteico 1 do Hospedeiro/genética , Sítios de Ligação , Cromossomos Bacterianos/química , Cromossomos Bacterianos/metabolismo , DNA/genética , DNA/metabolismo , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Fator Proteico 1 do Hospedeiro/metabolismo , Cinética , Agregados Proteicos , Ligação Proteica , Domínios Proteicos , Termodinâmica
14.
Connect Tissue Res ; 58(5): 464-478, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27791406

RESUMO

AIM OF THE STUDY: The attempt to limit the negative effects of polyester implants on the articular cavity by using preparations containing growth factors. MATERIALS AND METHODS: Polyester implants used for the reconstruction of a rabbit's cranial cruciate ligament (CCL) were saturated with autogenic platelet-rich plasma (PRP), antlerogenic stem cells MIC-1 and their homogenate prior to the surgery. Six months after CCL reconstruction, morphological, and biochemical blood tests were carried out, including proteinogram and acute phase proteins. The knee joints were also examined macro- and microscopically. RESULTS: The results, compared to the control group, showed a favorable effect of the PRP and homogenate of antlerogenic cells on limiting the inflammation caused by the presence of polyester implant in the knee joint. The addition of growth factors caused covering the implant faster with the recipient's connective tissue, thus contributing to reducing the inflammatory reaction of the articular capsule to the presence of polyester. At the same time, no enhanced local or general reaction of the rabbit organism was observed to the presence of xenogenic antlerogenic stem cells MIC-1 homogenate which, like the PRP, may provide an easily available source of growth factors, increasingly often used in regenerative medicine. CONCLUSIONS: Applying antlerogenic stem cells, their homogenate or PRP increases the volume of connective tissue that surrounds and intertwines polyester CCL implant, separating it from synovial cavity environment.


Assuntos
Lesões do Ligamento Cruzado Anterior , Ligamento Cruzado Anterior , Implantes Experimentais , Poliésteres , Transplante de Células-Tronco , Células-Tronco , Animais , Ligamento Cruzado Anterior/metabolismo , Ligamento Cruzado Anterior/patologia , Lesões do Ligamento Cruzado Anterior/metabolismo , Lesões do Ligamento Cruzado Anterior/patologia , Lesões do Ligamento Cruzado Anterior/terapia , Feminino , Masculino , Coelhos , Células-Tronco/metabolismo , Células-Tronco/patologia
15.
Acta Vet Hung ; 64(4): 425-435, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27993097

RESUMO

Canine congenital sensorineural deafness (CCSD) affects predisposed breeds of dogs and is primarily caused by an atrophy of the stria vascularis of the organ of Corti. The analysis of the brainstem auditory evoked response (BAER) is a reliable method for the evaluation of hearing in animals as it allows an accurate detection of unilateral or bilateral deafness. The occurrence of unilateral and bilateral deafness using the BAER was determined in a representative group of dogs in Poland, including Bull Terriers (n = 117), Australian Cattle Dogs (n = 62), English Setters (n = 32) and the Dogo Argentino (n = 32). Overall deafness, deafness in each dog breed and an association between deafness and phenotype were studied. Among the 243 dogs tested, 156 (81%) had a normal BAER, 27 (11%) were unilaterally deaf, and 12 (5%) were bilaterally deaf. The amplitudes and latencies of waves I, II, III, V, the V/I wave amplitude ratio, and wave I-V, I-III and III-V inter-peak intervals were recorded for each dog. Unilaterally and bilaterally deaf dogs were present in all the dog breeds studied. There were 17 (14.5%) deaf Bull Terriers, three (4.8%) deaf Australian Cattle Dogs, seven (21.9%) deaf English Setters, and 12 (37.5%) deaf Dogos Argentinos. Preventive BAER screening should be routinely performed in these four breeds to prevent the spread of genes responsible for deafness.


Assuntos
Doenças do Cão/congênito , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Predisposição Genética para Doença , Perda Auditiva Neurossensorial/veterinária , Animais , Doenças do Cão/genética , Cães , Potenciais Evocados Auditivos do Tronco Encefálico/genética , Perda Auditiva Neurossensorial/congênito , Perda Auditiva Neurossensorial/genética
16.
Front Mol Biosci ; 3: 36, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27517037

RESUMO

The Hfq protein was discovered in Escherichia coli as a host factor for bacteriophage Qß RNA replication. Subsequent studies indicated that Hfq is a pleiotropic regulator of bacterial gene expression. The regulatory role of Hfq is ascribed mainly to its function as an RNA-chaperone, facilitating interactions between bacterial non-coding RNA and its mRNA target. Thus, it modulates mRNA translation and stability. Nevertheless, Hfq is able to interact with DNA as well. Its role in the regulation of DNA-related processes has been demonstrated. In this mini-review, it is discussed how Hfq interacts with DNA and what is the role of this protein in regulation of DNA transactions. Particularly, Hfq has been demonstrated to be involved in the control of ColE1 plasmid DNA replication, transposition, and possibly also transcription. Possible mechanisms of these Hfq-mediated regulations are described and discussed.

17.
Vet Clin Pathol ; 44(3): 391-6, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26175133

RESUMO

BACKGROUND: Equine recurrent airway obstruction (RAO), also known as heaves, is one of the most common respiratory problems in older horses. When RAO-affected horses stay pastured or in a dust-free environment for a prolonged time, clinical signs as well as airway inflammation wane. A number of environmental, immunologic, infectious, and genetic factors play an important role in the pathogenesis of RAO, and the immunologic basis of this disease is still poorly understood. OBJECTIVES: The aim of this study was to investigate the concentrations of allergen-specific IgE in the serum of horses suffering from RAO and healthy controls. MATERIAL AND METHODS: The study included a group of 14 adult Polish Konik horses, kept in a standardized environment, and divided into 2 groups: 7 horses which did not have any respiratory problems comprised the control group and 7 horses with a history of RAO constituted the study group. A clinical and laboratory evaluation, endoscopic examination, and bronchoalveolar lavage (BAL) were performed in all horses. Sera of all horses were tested against allergens from 9 molds and 3 mites using the Heska Allercept assay. RESULTS: In the serologic tests, a statistically significant difference between both groups was found for specific IgE against mites, wherein Tyrophagus putrescentia correlated most clearly with RAO. There was no difference between groups for IgE specific against molds. CONCLUSION: On the basis of our observations and results, we conclude that RAO is associated with increased serum concentrations of specific serum IgE against mites, in particular T putrescentia.


Assuntos
Alérgenos/sangue , Doenças dos Cavalos/imunologia , Imunoglobulina E/imunologia , Ácaros/imunologia , Obstrução das Vias Respiratórias/veterinária , Alérgenos/imunologia , Animais , Ensaio de Imunoadsorção Enzimática/veterinária , Cavalos , Imunoglobulina E/sangue , Inflamação/veterinária
18.
Nucleic Acids Res ; 43(8): 4332-41, 2015 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-25824948

RESUMO

Hfq is a bacterial pleiotropic regulator that mediates several aspects of nucleic acids metabolism. The protein notably influences translation and turnover of cellular RNAs. Although most previous contributions concentrated on Hfq's interaction with RNA, its association to DNA has also been observed in vitro and in vivo. Here, we focus on DNA-compacting properties of Hfq. Various experimental technologies, including fluorescence microscopy imaging of single DNA molecules confined inside nanofluidic channels, atomic force microscopy and small angle neutron scattering have been used to follow the assembly of Hfq on DNA. Our results show that Hfq forms a nucleoprotein complex, changes the mechanical properties of the double helix and compacts DNA into a condensed form. We propose a compaction mechanism based on protein-mediated bridging of DNA segments. The propensity for bridging is presumably related to multi-arm functionality of the Hfq hexamer, resulting from binding of the C-terminal domains to the duplex. Results are discussed in regard to previous results obtained for H-NS, with important implications for protein binding related gene regulation.


Assuntos
DNA/química , Fator Proteico 1 do Hospedeiro/metabolismo , DNA/metabolismo , DNA/ultraestrutura , Microfluídica , Conformação de Ácido Nucleico , Ligação Proteica
19.
Acta Vet Scand ; 55: 45, 2013 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-24044656

RESUMO

BACKGROUND: This study was performed to determine the prevalence of ulcers in the gastric squamous and glandular mucosa in Polish pleasure horses. STUDY DESIGN: Medical records from gastroscopic examinations of 108 pleasure horses of different breeds were reviewed. The study population consisted of two groups; group I (n = 48) with horses that expressed mild clinical signs of gastric ulcer syndrome (EGUS) including poor appetite, slight weight loss or poor body condition, and group II (n = 60) with horses that had no signs of gastrointestinal problems. The age range was 4-10 years, including 5 males, 34 castrated males (geldings) and 69 mares. The prevalence, distribution and severity of gastric ulcers were recorded. Lesions involving the squamous mucosa and the glandular mucosa of the antrum and pylorus were graded and compared between groups. RESULTS: Significant difference was found in the presence and severity of gastric ulcers between the two groups of horses. The overall prevalence of gastric ulcers in the first group of horses (n = 48) was 59% while in the group of clinically healthy horses (n = 60) the prevalence of gastric lesion was 40% (P = 0.004). Almost 19% of horses from group I had between 6-10 lesions (EGUS score III) and nearly 19% had either >10 localized lesions or very large diffuse lesions (EGUS number score IV). The number of ulcerations in affected horses were significantly lower in group II compared to group I (P = 0.016) as 10% of horses had 6-10 lesions (EGUS number score III) and nearly 14% had either >10 localized lesions or very large diffuse lesions (EGUS number score IV). Gastroscopy revealed that nearly 32% of horses from the second group had an ulceration EGUS score ≥ II. DISCUSSION AND CONCLUSIONS: This study confirms that gastric ulcerations can be prevalent in apparently clinically normal pleasure horses and a complete gastroscopic examination including the examination of the pylorus is advisable to evaluate this syndrome.


Assuntos
Doenças dos Cavalos/diagnóstico , Úlcera Gástrica/veterinária , Animais , Feminino , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/patologia , Cavalos , Masculino , Polônia/epidemiologia , Úlcera Gástrica/diagnóstico , Úlcera Gástrica/epidemiologia , Úlcera Gástrica/patologia
20.
Acta Vet Scand ; 55: 58, 2013 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-23945316

RESUMO

BACKGROUND: The aim of this study was to investigate the effects of 8-hour road transport on plasma total antioxidant status (PTAS) and general clinical appearance in horses. FINDINGS: The study was conducted on a group of 60 horses of different breeds aged from 4 to 10 years. Venous blood was collected and a clinical examination was performed immediately before loading horses onto trailers for an 8 hour transport (I), immediately after unloading them from the trailer (II), and after a subsequent 24 hour stall rest (III). The ferric-reducing ability of plasma (FRAP) was used to determine PTAS. The transportation significantly increased respiratory and heart rates. The average PTAS increased during the three subsequent samplings: I: 170±77 (µmol/l) II: 204±70 (µmol/l) III: 221±74 (µmol/l). CONCLUSION: Long-distance transport increased the PTAS horses, as well as respiratory and heart rates.


Assuntos
Antioxidantes/metabolismo , Cavalos/sangue , Estresse Oxidativo/fisiologia , Meios de Transporte , Animais , Feminino , Masculino , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA