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1.
J Fungi (Basel) ; 9(12)2023 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-38132733

RESUMO

Pet hedgehogs, which are increasingly favoured companions, have garnered attention due to their potential as carriers of zoonotic diseases. These small insectivorous mammals, native to Europe, Asia, and Africa, are commonly kept as pets. The encroachment of humans into hedgehog habitats has brought these animals closer to people, raising concerns about disease transmission. This article reviews the current knowledge regarding zoonotic disease associated with pet hedgehogs, with a particular focus on mycotic infections caused by Trichophyton erinacei. Data from various regions and hedgehog species are synthesised to assess the significance of pet hedgehogs as potential reservoirs and transmitters of zoonotic pathogens. Our study highlights the importance of understanding the health risks associated with pet hedgehogs and underscores the need for continued research to mitigate zoonotic disease transmission from these potentially disease-carrying companions.

2.
Animals (Basel) ; 12(18)2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36139247

RESUMO

Fungal skin diseases are well-recognized diseases with public health implications. The study provides a comprehensive overview and aims to determine the rate of positive fungal cultures to identify the most common fungal species in guinea pigs and rabbits and to determine the rate of asymptomatic carriers in healthy pet animals. This knowledge is essential for understanding disease transmission dynamics and epidemiological situation problems. A total of 167 animals (64 rabbits and 103 guinea pigs) were investigated in this study. The fungi of the genus Penicillium, Rhizopus, Mucor, Cladosporium, and Aspergillus were the most common in the examined animals, and they were isolated from 162 (97%) of the animals enrolled. No fungal growth was observed in 5 animals. In 15 cases (8.98%), we found pathogenic zoonotic dermatophytes (Trichophyton mentagrophytes), which caused several health problems in two humans in contact with affected animals. This study presents the prevalence of fungal flora in pet guinea pigs and rabbits in Slovakia.

3.
Acta Vet Hung ; 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35895536

RESUMO

The population and distribution of the European brown bear (Ursus arctos) in Slovakia are expanding as bears were observed beyond the southern border of the country in Hungary. This study presents the authors' experience with field anaesthesia of wild brown bears trapped in a custom-made container trap and of free-ranging individuals. A total of 25 bears were captured and translocated using a specially designed metal cage trap. The study compared the effectiveness of three anaesthetic protocols in managing both free-ranging and trapped bears. For juveniles, or small adults up to 70 kg body weight (BW), ketamine-xylazine mixture was used at doses of 3.0-4.0 mg kg-1 ketamine and 1.0-1.5 mg kg-1 xylazine BW. The immobilisation of free-ranging bears, which are usually attracted by municipal solid garbage, was performed remotely using PneuDart darts with 2-3 ml of anaesthetics. For this purpose, tiletamine-zolazepam-detomidine (T-Z-D) was preferred at a dose of 1.7-2.5 (T) mg kg-1, 1.7-2.5 (Z) mg kg-1, and 0.1-0.2 (D) mg kg-1 BW. Induction time was from 7 to 18 min post darting with the average of 12.04 min. The same combination was applied to bears trapped in a container trap, with anaesthesia lasting from 40 to 150 min. If T-Z-D was used, no further anaesthetic was needed. In all cases, anaesthesia was antagonised by atipamezole at a dose of 0.15-0.225 mg kg-1 BW. Atipamezole was injected at a half dose intramuscularly and a half dose subcutaneously at the time when the palpebral reflex reappeared and the bear was able to move his tongue. It was shown that the T-Z-D mixture is a safe, low-volume anaesthetic darting protocol that is reversible, has minimal adverse effects on physiological parameters, and has a sufficient duration. The results can be used to manage large carnivore populations in the Carpathian region.

4.
Cell ; 185(8): 1402-1413.e21, 2022 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-35366416

RESUMO

The Avars settled the Carpathian Basin in 567/68 CE, establishing an empire lasting over 200 years. Who they were and where they came from is highly debated. Contemporaries have disagreed about whether they were, as they claimed, the direct successors of the Mongolian Steppe Rouran empire that was destroyed by the Turks in ∼550 CE. Here, we analyze new genome-wide data from 66 pre-Avar and Avar-period Carpathian Basin individuals, including the 8 richest Avar-period burials and further elite sites from Avar's empire core region. Our results provide support for a rapid long-distance trans-Eurasian migration of Avar-period elites. These individuals carried Northeast Asian ancestry matching the profile of preceding Mongolian Steppe populations, particularly a genome available from the Rouran period. Some of the later elite individuals carried an additional non-local ancestry component broadly matching the steppe, which could point to a later migration or reflect greater genetic diversity within the initial migrant population.


Assuntos
Povo Asiático , DNA Antigo , Genética Populacional , Povo Asiático/genética , Genoma , História Antiga , Migração Humana/história , Humanos , Enxofre
5.
Br J Pharmacol ; 179(5): 938-957, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-33822374

RESUMO

To study the pathophysiology of human cardiac diseases and to develop novel treatment strategies, complex interactions of cardiac cells on cellular, tissue and on level of the whole heart need to be considered. As in vitro cell-based models do not depict the complexity of the human heart, animal models are used to obtain insights that can be translated to human diseases. Mice are the most commonly used animals in cardiac research. However, differences in electrophysiological and mechanical cardiac function and a different composition of electrical and contractile proteins limit the transferability of the knowledge gained. Moreover, the small heart size and fast heart rate are major disadvantages. In contrast to rodents, electrophysiological, mechanical and structural cardiac characteristics of rabbits resemble the human heart more closely, making them particularly suitable as an animal model for cardiac disease research. In this review, various methodological approaches for the generation of transgenic rabbits for cardiac disease research, such as pronuclear microinjection, the sleeping beauty transposon system and novel genome-editing methods (ZFN and CRISPR/Cas9)will be discussed. In the second section, we will introduce the different currently available transgenic rabbit models for monogenic cardiac diseases (such as long QT syndrome, short-QT syndrome and hypertrophic cardiomyopathy) in detail, especially in regard to their utility to increase the understanding of pathophysiological disease mechanisms and novel treatment options. LINKED ARTICLES: This article is part of a themed issue on Preclinical Models for Cardiovascular disease research (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.5/issuetoc.


Assuntos
Cardiomiopatia Hipertrófica , Cardiopatias , Síndrome do QT Longo , Animais , Animais Geneticamente Modificados , Arritmias Cardíacas , Cardiopatias/genética , Camundongos , Coelhos
6.
Acta Vet Hung ; 69(3): 298-302, 2021 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-34520389

RESUMO

This paper presents a clinical case report of a golden eagle (Aquila chrysaetos) with foreign bodies (stones) in its proventriculus. The case deals with the identification, management and removal of foreign objects identified in the gastrointestinal tract. A surgical removal by proventriculotomy under general anaesthesia was attempted. The surgery and the recovery were uneventful, and the follow-up after six months revealed no complications. To the best of our knowledge, there are no other reports of successful foreign body removal by proventriculotomy in the golden eagle.


Assuntos
Doenças das Aves , Águias , Corpos Estranhos , Animais , Corpos Estranhos/cirurgia , Corpos Estranhos/veterinária , Propilaminas , Proventrículo , Sulfetos
7.
Animals (Basel) ; 10(12)2020 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-33353114

RESUMO

The seasonal dynamics of the prevalence, abundance, and mean intensity of egg excretion by the nematode parasite Baylisascaris transfuga in the European brown bear (Ursus arctos) were monitored relative to environmental factors (mean temperature, humidity, and temperature) over three years. The prevalence, abundance, and mean intensity of egg excretion tended to increase from spring to autumn throughout the monitoring period. The seasonal prevalence (84.2-90.6%), abundance (470.2-545.3 eggs per gramme (EPG) of faeces), mean intensity of excretion (558.3-602.1 EPG), and number of eggs (1150 EPG) were highest in autumn. The prevalence of eggs (up to 48.5%), abundance (37.8-60.6 EPG), and mean intensity of excretion (94.4-125.0 EPG) were high in winter, despite the period of hibernation. The seasonal dynamics of B. transfuga abundance in bears, the mean temperature between spring and autumn, and the seasonal trend of increase in intensity of egg excretion with temperature from winter to summer were interrelated. Abundance differed significantly between winter and autumn, spring and autumn, and summer and autumn (p < 0.0001) in all years and between spring and summer in 2016 (p < 0.005), 2017 (p < 0.05). B. transfuga abundance differed significantly between the seasons over the three years only in spring (p ≤ 0.0001).

8.
Br J Pharmacol ; 177(16): 3744-3759, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32436214

RESUMO

BACKGROUND AND PURPOSE: Reliable prediction of pro-arrhythmic side effects of novel drug candidates is still a major challenge. Although drug-induced pro-arrhythmia occurs primarily in patients with pre-existing repolarisation disturbances, healthy animals are employed for pro-arrhythmia testing. To improve current safety screening, transgenic long QT (LQTS) rabbit models with impaired repolarisation reserve were generated by overexpressing loss-of-function mutations of human HERG (HERG-G628S, loss of IKr ; LQT2), KCNE1 (KCNE1-G52R, decreased IKs ; LQT5), or both transgenes (LQT2-5) in the heart. EXPERIMENTAL APPROACH: Effects of K+ channel blockers on cardiac repolarisation and arrhythmia susceptibility were assessed in healthy wild-type (WT) and LQTS rabbits using in vivo ECG and ex vivo monophasic action potential and ECG recordings in Langendorff-perfused hearts. KEY RESULTS: LQTS models reflect patients with clinically "silent" (LQT5) or "manifest" (LQT2 and LQT2-5) impairment in cardiac repolarisation reserve: they were more sensitive in detecting IKr -blocking (LQT5) or IK1 /IKs -blocking (LQT2 and LQT2-5) properties of drugs compared to healthy WT animals. Impaired QT-shortening capacity at fast heart rates was observed due to disturbed IKs function in LQT5 and LQT2-5. Importantly, LQTS models exhibited higher incidence, longer duration, and more malignant types of ex vivo arrhythmias than WT. CONCLUSION AND IMPLICATIONS: LQTS models represent patients with reduced repolarisation reserve due to different pathomechanisms. As they demonstrate increased sensitivity to different specific ion channel blockers (IKr blockade in LQT5 and IK1 and IKs blockade in LQT2 and LQT2-5), their combined use could provide more reliable and more thorough prediction of (multichannel-based) pro-arrhythmic potential of novel drug candidates.


Assuntos
Síndrome do QT Longo , Preparações Farmacêuticas , Potenciais de Ação , Animais , Animais Geneticamente Modificados , Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/genética , Ventrículos do Coração , Humanos , Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/genética , Coelhos
9.
J Nucl Med ; 60(12): 1818-1824, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31302634

RESUMO

The LFER 150 PET/CT device (large-field-of-view extreme-resolution portable research imager) is a system for nonhuman primate (NHP) imaging. The objective of this study was to evaluate the performance of the system using the National Electrical Manufacturers Association NU 4-2008 standard protocol. As a preliminary in vivo evaluation of the system, a PET measurement in an NHP was also performed. Methods: Resolution, sensitivity, image quality, and noise-equivalent count rate (NECR) were measured. NECR measurement was performed with a ratlike phantom and a monkeylike phantom. A Derenzo phantom experiment was performed to test the resolution using 3-dimensional ordered-subset expectation maximization reconstruction. One cynomolgus monkey (4.5 kg, intravenous ketamine/xylazine anesthesia) was examined with the dopamine transporter radioligand 18F-FE-PE2I (94 MBq) to evaluate the in vivo performance of the system. List-mode PET data acquired for 93 min were reconstructed into 38 frames with the Tera-Tomo 3-dimensional engine. Binding potential for caudate nucleus, putamen, and substantia nigra was evaluated using the simplified reference tissue model. Results: Radial full-width half-maximum resolution using Fourier rebinning and a 2-dimensional filtered backprojection algorithm was less than 2.2 mm and less than 3.2 mm in the central 60-mm-diameter and 140-mm-diameter regions, respectively. Maximum sensitivity in the 400- to 600-keV and 250- to 750-keV energy windows was 30.03 cps/kBq (3.3%) and 49.11 cps/kBq (5.4%), respectively. The uniformity in the image-quality phantom was 3.3%, and the spillover ratio for air and water was 0.1. The peak of the NECR curve was 430 kcps (at 115 MBq) with the ratlike phantom and 78 kcps (at 139 MBq) with the monkeylike phantom. Rods of the Derenzo phantom with 1-mm diameter could be distinguished by eye. In the NHP experiment, binding potentials in the caudate, putamen, and substantia nigra (4.9, 4.9, and 1, respectively) were similar to those previously reported using the same radioligand and a high-resolution research tomograph. Conclusion: The results obtained from phantom experiments and 1 representative PET measurement in an NHP confirm that the LFER 150 is a high-resolution PET/CT system with suitable performance for brain imaging in NHPs.


Assuntos
Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/instrumentação , Razão Sinal-Ruído , Animais , Macaca fascicularis
10.
Elife ; 82019 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-31355745

RESUMO

Plasma membrane-located transport proteins are key adaptations for obligate intracellular Microsporidia parasites, because they can use them to steal host metabolites the parasites need to grow and replicate. However, despite their importance, the functions and substrate specificities of most Microsporidia transporters are unknown. Here, we provide functional data for a family of transporters conserved in all microsporidian genomes and also in the genomes of related endoparasites. The universal retention among otherwise highly reduced genomes indicates an important role for these transporters for intracellular parasites. Using Trachipleistophora hominis, a Microsporidia isolated from an HIV/AIDS patient, as our experimental model, we show that the proteins are ATP and GTP transporters located on the surface of parasites during their intracellular growth and replication. Our work identifies a new route for the acquisition of essential energy and nucleotides for a major group of intracellular parasites that infect most animal species including humans.


Assuntos
Trifosfato de Adenosina/metabolismo , Guanosina Trifosfato/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Microsporídios/genética , Microsporídios/metabolismo , Animais , Linhagem Celular , Biologia Computacional , Sequência Conservada , Genoma Fúngico , Microsporídios/crescimento & desenvolvimento , Coelhos
11.
Vector Borne Zoonotic Dis ; 18(4): 206-213, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29437548

RESUMO

In central Europe, at least three flaviviruses circulate among vectors and vertebrate hosts. West Nile virus (WNV) and Usutu virus (USUV) are mosquito-borne viruses maintained in the nature by enzootic cycle between mosquitoes and birds. Tick-borne encephalitis virus (TBEV) is a flavivirus causing annual human cases in Slovakia. The aim of this study is the prevalence assessment of flavivirus infections in horses (n = 145) and birds (n = 109) by enzyme-linked immunosorbent assay (ELISA) and confirmation by neutralization test (VNT). WNV antibodies have been detected in 11.7% of tested horses and 11.9% of tested birds and confirmed in 6.9% of horse and 9.2% of bird samples. None of the WNV seropositive or dubious horses had WNV IgM (ELISA), and none of the tested horses had USUV neutralizing antibodies. Autochthonous WNV infections have been confirmed in 16.7% of horses without international travelling history. Most of them were from western Slovakia with known endemic WNV transmission. An autochthonous WNV infection in a horse from highland area of Kremnické vrchy (central Slovakia) with unknown data of WNV circulation and without travelling history was detected. TBEV antibody was detected in 6.2% of horses and in 3.4% has been confirmed. In two horses, WNV and TBEV infection could not be distinguished. Confirmed WNV seropositive were eight raptors showing nonspecific signs or suffering from trauma, one white stork, and one house sparrow. The sparrow was caught in a locality in eastern Slovakia, where WNV RNA had been previously detected in sparrows. USUV neutralizing antibodies were present in pooled sample from four Eurasian great tits. Because of insufficient volume, TBEV VNT was not carried out in birds. Results further prove the endemicity of WNV and other vector-borne flaviviruses in natural and accidental hosts in Slovakia, giving better insight in flavivirus epidemiology in European countries in general.


Assuntos
Doenças das Aves/virologia , Infecções por Flavivirus/veterinária , Doenças dos Cavalos/virologia , Animais , Anticorpos Antivirais/análise , Doenças das Aves/epidemiologia , Aves/imunologia , Aves/virologia , Ensaio de Imunoadsorção Enzimática , Infecções por Flavivirus/epidemiologia , Doenças dos Cavalos/epidemiologia , Cavalos/imunologia , Cavalos/virologia , Estudos Soroepidemiológicos , Eslováquia
12.
Genome Biol Evol ; 9(2): 480-487, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28164241

RESUMO

Plasma membrane-located nucleotide transport proteins (NTTs) underpin the lifestyle of important obligate intracellular bacterial and eukaryotic pathogens by importing energy and nucleotides from infected host cells that the pathogens can no longer make for themselves. As such their presence is often seen as a hallmark of an intracellular lifestyle associated with reductive genome evolution and loss of primary biosynthetic pathways. Here, we investigate the phylogenetic distribution of NTT sequences across the domains of cellular life. Our analysis reveals an unexpectedly broad distribution of NTT genes in both host-associated and free-living prokaryotes and eukaryotes. We also identify cases of within-bacteria and bacteria-to-eukaryote horizontal NTT transfer, including into the base of the oomycetes, a major clade of parasitic eukaryotes. In addition to identifying sequences that retain the canonical NTT structure, we detected NTT gene fusions with HEAT-repeat and cyclic nucleotide binding domains in Cyanobacteria, pathogenic Chlamydiae and Oomycetes. Our results suggest that NTTs are versatile functional modules with a much wider distribution and a broader range of potential roles than has previously been appreciated.


Assuntos
Proteínas de Bactérias/genética , Evolução Molecular , Proteínas de Transporte de Nucleotídeos/genética , Filogenia , Chlamydia/classificação , Chlamydia/genética , Chlamydia/patogenicidade , Cianobactérias/classificação , Cianobactérias/genética , Oomicetos/classificação , Oomicetos/genética , Simbiose/genética
13.
Br J Pharmacol ; 173(12): 2046-61, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27076034

RESUMO

BACKGROUND AND PURPOSE: The reliable assessment of proarrhythmic risk of compounds under development remains an elusive goal. Current safety guidelines focus on the effects of blocking the KCNH2/HERG ion channel-in tissues and animals with intact repolarization. Novel models with better predictive value are needed that more closely reflect the conditions in patients with cardiac remodelling and reduced repolarization reserve. EXPERIMENTAL APPROACH: We have developed a model for the long QT syndrome type-5 in rabbits (LQT5 ) with cardiac-specific overexpression of a mutant (G52R) KCNE1 ß-subunit of the channel that carries the slow delayed-rectifier K(+) -current (IKs ). ECG parameters, including short-term variability of the QT interval (STVQT ), a biomarker for proarrhythmic risk, and arrhythmia development were recorded. In vivo, arrhythmia susceptibility was evaluated by i.v. administration of the IKr blocker dofetilide. K(+) currents were measured with the patch-clamp technique. KEY RESULTS: Patch-clamp studies in ventricular myocytes isolated from LQT5 rabbits revealed accelerated IKs and IKr deactivation kinetics. At baseline, LQT5 animals exhibited slightly but significantly prolonged heart-rate corrected QT index (QTi) and increased STVQT . Dofetilide provoked Torsade-de-Pointes arrhythmia in a greater proportion of LQT5 rabbits, paralleled by a further increase in STVQT . CONCLUSION AND IMPLICATIONS: We have created a novel transgenic LQT5 rabbit model with increased susceptibility to drug-induced arrhythmias that may represent a useful model for testing proarrhythmic potential and for investigations of the mechanisms underlying arrhythmias and sudden cardiac death due to repolarization disturbances.


Assuntos
Genes Dominantes , Síndrome do QT Longo/genética , Mutação , Canais de Potássio de Abertura Dependente da Tensão da Membrana/genética , Animais , Animais Geneticamente Modificados , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Coelhos , Reação em Cadeia da Polimerase em Tempo Real
14.
Arch Virol ; 161(6): 1679-83, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27001305

RESUMO

West Nile virus (WNV) is a mosquito-borne neurotropic pathogen that presents a major public health concern. Information on WNV prevalence and circulation in Slovakia is insufficient. Oral and cloacal swabs and bird brain samples were tested for flavivirus RNA by RT-PCR using newly designed generic primers. The species designation was confirmed by sequencing. WNV was detected in swab and brain samples, whereas one brain sample was positive for tick-borne encephalitis virus (TBEV). The WNV sequences clustered with lineages 1 and 2. These results confirm the circulation of WNV in birds in Slovakia and emphasize the risk of infection of humans and horses.


Assuntos
Vírus da Encefalite Transmitidos por Carrapatos/genética , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Vírus do Nilo Ocidental/genética , Vírus do Nilo Ocidental/isolamento & purificação , Animais , Doenças das Aves/virologia , Aves/virologia , Primers do DNA/genética , Vetores de Doenças , Encefalite Transmitida por Carrapatos/transmissão , Cavalos , Humanos , Filogenia , RNA Viral/genética , RNA Viral/isolamento & purificação , Eslováquia , Febre do Nilo Ocidental/transmissão , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental/classificação
15.
Front Plant Sci ; 5: 153, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24808897

RESUMO

The loss of key biosynthetic pathways is a common feature of important parasitic protists, making them heavily dependent on scavenging nutrients from their hosts. This is often mediated by specialized transporter proteins that ensure the nutritional requirements of the parasite are met. Over the past decade, the completion of several parasite genome projects has facilitated the identification of parasite transporter proteins. This has been complemented by functional characterization of individual transporters along with investigations into their importance for parasite survival. In this review, we summarize the current knowledge on transporters from parasitic protists and highlight commonalities and differences in the transporter repertoires of different parasitic species, with particular focus on characterized transporters that act at the host-pathogen interface.

16.
Phys Med Biol ; 59(11): 2727-46, 2014 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-24800813

RESUMO

The contrast recovery coefficients (CRC) were evaluated for five different small animal PET scanners: GE Explore Vista, Genisys4, MiniPET-2, nanoScan PC and Siemens Inveon. The NEMA NU-4 2008 performance test with the suggested image quality phantom (NU4IQ) does not allow the determination of the CRC values for the hot regions in the phantom. This drawback of NU4IQ phantom motivated us to develop a new method for this purpose. The method includes special acquisition and reconstruction protocols using the original phantom, and results in an artificially merged image enabling the evaluation of CRC values. An advantageous feature of this method is that it stops the cold wall effect from distorting the CRC calculation. Our suggested protocol results in a set of CRC values contributing to the characterization of small animal PET scanners. GATE simulations were also performed to validate the new method and verify the evaluated CRC values. We also demonstrated that the numerical values of this parameter depend on the actual object contrast of the hot region(s) and this mainly comes from the spillover effect. This effect was also studied while analysing the background activity level around the hot rods. We revealed that the calculated background mean values depended on the target contrast in a scanner specific manner. Performing the artificially merged imaging procedure and additional simulations using the micro hollow sphere (MHS) phantom geometry, we also proved that the inactive wall around the hot spheres can have a remarkable impact on the calculated CRC. In conclusion, we have shown that the proposed artificial merging procedure and the commonly used NU4IQ phantom prescribed by the NEMA NU-4 can easily deliver reliable CRC data otherwise unavailable for the NU4IQ phantom in the conventional protocol or the MHS phantom.


Assuntos
Temperatura Baixa , Imagens de Fantasmas , Tomografia por Emissão de Pósitrons/instrumentação , Animais , Artefatos , Método de Monte Carlo
19.
J Nucl Med ; 54(10): 1825-32, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23990683

RESUMO

UNLABELLED: nanoScan is a high-resolution integrated system for consecutive PET and MR imaging of small laboratory animals. We evaluated the performance of the system, using the NEMA NU 4-2008 protocol for the PET component and the NEMA MS 1-2007, MS 2-2008, and MS 3-2007 standards for the MR imaging component. METHODS: The imaging system uses magnetically shielded position-sensitive photomultiplier tubes and a compact 1-T permanent-magnet MR imaging platform. Spatial resolution, sensitivity, counting rate capabilities, and image quality parameters were evaluated in accordance with the aforementioned NEMA standards. Further in vivo evaluation experiments complement the physical validation results. RESULTS: The spatial resolution of the PET system enabled the 0.8-mm rods of a Derenzo phantom to be resolved. With point source and 2-dimensional filtered backprojection reconstruction, the resolution varied from 1.50 to 2.01 mm in full width at half maximum in the radial direction and from 1.32 to 1.65 mm in the tangential direction within the radius of 25 mm. Peak absolute sensitivity was 8.41%. Scatter fraction was 17.3% and 34.0%, and maximum noise-equivalent counting rate was 406 and 119 kcps in the mouselike and ratlike phantom, respectively. The image quality test found a nonuniformity of 3.52% and a spillover ratio of 6.2% and 5.8% in water and air, respectively. In testing of the MR imaging component, artifact-free images with high signal-to-noise ratio were recorded. Geometric distortion was below 5%, and image uniformity was at least 94.5% and 96.6% for the 60- and 35-mm radiofrequency coils, respectively. CONCLUSION: The nanoScan integrated small-animal PET/MR imaging system has excellent spatial resolution and sensitivity. The performance characteristics of the PET and the MR imaging components are not compromised as a result of their integration onto a single platform. Because of its combination of features and performance parameters, the system provides crucial advantages for preclinical imaging studies over existing PET/CT systems, especially in neurologic and oncologic research.


Assuntos
Imageamento por Ressonância Magnética/instrumentação , Tomografia por Emissão de Pósitrons/instrumentação , Animais , Camundongos , Ratos , Razão Sinal-Ruído , Integração de Sistemas
20.
Nucleic Acids Res ; 41(13): 6715-28, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23666629

RESUMO

Nonsense-mediated mRNA decay (NMD) is a eukaryotic quality control system that recognizes and degrades transcripts containing NMD cis elements in their 3'untranslated region (UTR). In yeasts, unusually long 3'UTRs act as NMD cis elements, whereas in vertebrates, NMD is induced by introns located >50 nt downstream from the stop codon. In vertebrates, splicing leads to deposition of exon junction complex (EJC) onto the mRNA, and then 3'UTR-bound EJCs trigger NMD. It is proposed that this intron-based NMD is vertebrate specific, and it evolved to eliminate the misproducts of alternative splicing. Here, we provide evidence that similar EJC-mediated intron-based NMD functions in plants, suggesting that this type of NMD is evolutionary conserved. We demonstrate that in plants, like in vertebrates, introns located >50 nt from the stop induces NMD. We show that orthologs of all core EJC components are essential for intron-based plant NMD and that plant Partner of Y14 and mago (PYM) also acts as EJC disassembly factor. Moreover, we found that complex autoregulatory circuits control the activity of plant NMD. We demonstrate that expression of suppressor with morphogenic effect on genitalia (SMG)7, which is essential for long 3'UTR- and intron-based NMD, is regulated by both types of NMD, whereas expression of Barentsz EJC component is downregulated by intron-based NMD.


Assuntos
Regulação da Expressão Gênica de Plantas , Íntrons , Degradação do RNAm Mediada por Códon sem Sentido , Proteínas de Plantas/fisiologia , Regiões 3' não Traduzidas , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/fisiologia , Proteínas de Transporte/genética , Códon de Terminação , Homeostase , Proteínas de Ligação a RNA/metabolismo
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