Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Int J Mol Sci ; 21(12)2020 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-32604724

RESUMEN

In the 21st century, three highly pathogenic betacoronaviruses have emerged, with an alarming rate of human morbidity and case fatality. Genomic information has been widely used to understand the pathogenesis, animal origin and mode of transmission of coronaviruses in the aftermath of the 2002-2003 severe acute respiratory syndrome (SARS) and 2012 Middle East respiratory syndrome (MERS) outbreaks. Furthermore, genome sequencing and bioinformatic analysis have had an unprecedented relevance in the battle against the 2019-2020 coronavirus disease 2019 (COVID-19) pandemic, the newest and most devastating outbreak caused by a coronavirus in the history of mankind. Here, we review how genomic information has been used to tackle outbreaks caused by emerging, highly pathogenic, betacoronavirus strains, emphasizing on SARS-CoV, MERS-CoV and SARS-CoV-2. We focus on shared genomic features of the betacoronaviruses and the application of genomic information to phylogenetic analysis, molecular epidemiology and the design of diagnostic systems, potential drugs and vaccine candidates.


Asunto(s)
Betacoronavirus/genética , Infecciones por Coronavirus/virología , Genoma Viral , Pandemias/prevención & control , Neumonía Viral/virología , Animales , Betacoronavirus/inmunología , COVID-19 , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/tratamiento farmacológico , Diseño de Fármacos , Genes Virales , Humanos , Coronavirus del Síndrome Respiratorio de Oriente Medio/genética , Epidemiología Molecular , Filogenia , Neumonía Viral/diagnóstico , Neumonía Viral/tratamiento farmacológico , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/genética , SARS-CoV-2 , Síndrome Respiratorio Agudo Grave/virología , Vacunas Virales/genética , Vacunas Virales/inmunología
2.
Virol J ; 9: 216, 2012 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-22998755

RESUMEN

A colony of domestic rabbits in Tennessee, USA, experienced a high-mortality (~90%) outbreak of enterocolitis. The clinical characteristics were one to six days of lethargy, bloating, and diarrhea, followed by death. Heavy intestinal coccidial load was a consistent finding as was mucoid enteropathy with cecal impaction. Preliminary analysis by electron microscopy revealed the presence of virus-like particles in the stool of one of the affected rabbits. Analysis using the Virochip, a viral detection microarray, suggested the presence of an astrovirus, and follow-up PCR and sequence determination revealed a previously uncharacterized member of that family. Metagenomic sequencing enabled the recovery of the complete viral genome, which contains the characteristic attributes of astrovirus genomes. Attempts to propagate the virus in tissue culture have yet to succeed. Although astroviruses cause gastroenteric disease in other mammals, the pathogenicity of this virus and the relationship to this outbreak remains to be determined. This study therefore defines a viral species and a potential rabbit pathogen.


Asunto(s)
Astroviridae/genética , Genoma Viral , ARN Viral/genética , Análisis de Secuencia de ADN , Animales , Astroviridae/aislamiento & purificación , Infecciones por Astroviridae/veterinaria , Infecciones por Astroviridae/virología , Enterocolitis/veterinaria , Enterocolitis/virología , Heces/virología , Gastroenteritis/veterinaria , Gastroenteritis/virología , Microscopía Electrónica , Datos de Secuencia Molecular , Conejos , Tennessee , Cultivo de Virus
3.
J Crohns Colitis ; 16(5): 768-777, 2022 06 24.
Artículo en Inglés | MEDLINE | ID: mdl-34788420

RESUMEN

BACKGROUND: Children with inflammatory bowel disease [IBD] are disproportionally affected by recurrent Clostridioides difficile infection [rCDI]. Although faecal microbiota transplantation [FMT] has been used with good efficacy in adults with IBD, little is known about outcomes associated with FMT in paediatric IBD. METHODS: We performed a retrospective review of FMT at 20 paediatric centres in the USA from March 2012 to March 2020. Children with and without IBD were compared with determined differences in the efficacy of FMT for rCDI. In addition, children with IBD with and without a successful outcome were compared with determined predictors of success. Safety data and IBD-specific outcomes were obtained. RESULTS: A total of 396 paediatric patients, including 148 with IBD, were included. Children with IBD were no less likely to have a successful first FMT then the non-IBD affected cohort [76% vs 81%, p = 0.17]. Among children with IBD, patients were more likely to have a successful FMT if they received FMT with fresh stool [p = 0.03], were without diarrhoea prior to FMT [p = 0.03], or had a shorter time from rCDI diagnosis until FMT [p = 0.04]. Children with a failed FMT were more likely to have clinically active IBD post-FMT [p = 0.002] and 19 [13%] patients had an IBD-related hospitalisation in the 3-month follow-up. CONCLUSIONS: Based on the findings from this large US multicentre cohort, the efficacy of FMT for the treatment of rCDI did not differ in children with IBD. Failed FMT among children with IBD was possibly related to the presence of clinically active IBD.


Asunto(s)
Clostridioides difficile , Infecciones por Clostridium , Enfermedades Inflamatorias del Intestino , Adulto , Niño , Enfermedad Crónica , Infecciones por Clostridium/complicaciones , Infecciones por Clostridium/terapia , Trasplante de Microbiota Fecal/efectos adversos , Heces , Humanos , Enfermedades Inflamatorias del Intestino/complicaciones , Enfermedades Inflamatorias del Intestino/terapia , Recurrencia , Resultado del Tratamiento
4.
J S Afr Vet Assoc ; 92(0): e1-e4, 2021 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-33970003

RESUMEN

Domestic dogs (Canis familiaris) may serve as a reservoir or a sentinel for infectious disease pathogens that can affect human and wildlife health. To understand the role of tick-borne diseases in rural and lesser developed regions, we investigated the prevalence of several tick-borne pathogens in communal dogs of Zimbabwe. Blood samples from 225 dogs in northwest Zimbabwe were assessed by serology for Ehrlichia canis, Anaplasma phagocytophilum and Borrelia burgdorferi, and 241 samples were assessed by polymerase chain reaction (PCR) for Ehrlichia. There was a high seroprevalence (73%) of E. canis-specific antibodies in domestic dogs in northwest Zimbabwe, but follow up analyses via PCR and genetic sequencing indicated only 7.5% of the canines were actively infected with the organism. Whilst indicating that an organism serologically related to E. canis is likely present in the region, this data also shows that the organism is currently present in a relative minority of the domestic dogs in the region. Its presence as evidenced by both serologic and PCR analysis is significant because of the 'one health' paradigm, where humans and wildlife may be affected by the exposure to this pathogen in domestic dogs.


Asunto(s)
Enfermedades de los Perros/diagnóstico , Enfermedades por Picaduras de Garrapatas/veterinaria , Animales , Enfermedades de los Perros/sangre , Enfermedades de los Perros/epidemiología , Perros , Femenino , Masculino , Reacción en Cadena de la Polimerasa , Pruebas Serológicas/veterinaria , Enfermedades por Picaduras de Garrapatas/sangre , Enfermedades por Picaduras de Garrapatas/diagnóstico , Enfermedades por Picaduras de Garrapatas/epidemiología , Zimbabwe/epidemiología
5.
Curr Infect Dis Rep ; 12(6): 465-70, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21308556

RESUMEN

Non-albicans Candida species have increasingly been identified as the cause of vulvovaginitis. In vitro and in vivo data indicate that the various non-albicans Candida species identified in the lower genital tract differ considerably with regard to epidemiology, virulence or vaginal pathogenicity, and antimycotic drug susceptibility. Clinical experience indicates reduced virulence of these organisms in the lower genital tract, and their causal role in a symptomatic patient requires careful case-by-case determination rather than routine administration of antimycotic therapy. Accordingly, vaginal Candida isolates deserve species identification and consideration of pathogenic potential and antifungal susceptibility before therapeutic decisions are made.

6.
Vet Clin North Am Small Anim Pract ; 50(5): 1001-1011, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32563530

RESUMEN

Feline infectious peritonitis (FIP) is a mysterious and lethal disease of cats. The causative agent, feline coronavirus (FCoV), is ubiquitous in most feline populations, yet the disease is sporadic in nature. Mutations in the infecting virus combined with an inappropriate immune response to the FCoV contribute to the development of FIP. Diagnosis can be challenging because signs may be vague, clinical pathology parameters are nonspecific, and the gold standard for diagnosis is invasive: histopathology of affected tissue. This article discusses the developments in the understanding of this disease as well as the progress in diagnosis and treatment.


Asunto(s)
Coronavirus Felino , Peritonitis Infecciosa Felina/virología , Adenosina Trifosfato/análogos & derivados , Adenosina Trifosfato/uso terapéutico , Animales , Antivirales/uso terapéutico , Gatos , Coronavirus Felino/genética , Peritonitis Infecciosa Felina/diagnóstico , Peritonitis Infecciosa Felina/patología , Peritonitis Infecciosa Felina/terapia , Predisposición Genética a la Enfermedad , Pirrolidinas/uso terapéutico , Ácidos Sulfónicos
7.
J Am Vet Med Assoc ; 257(9): 929-932, 2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-33064607

RESUMEN

OBJECTIVE: To evaluate the effect of UV germicidal irradiation of the air on the incidence of upper respiratory tract infections (URIs) in kittens in a nursery. ANIMALS: 4- to 8-week-old kittens admitted to a kitten nursery in 2016 and 2018. PROCEDURES: 2 UV germicidal irradiation systems (1 within the heating, ventilation, and air conditioning system and 1 attached to the ceiling) were installed in a kitten nursery. Data were collected on the number of kittens in which a URI was diagnosed by means of a physical examination. The incidence of URIs was compared between 2016, when no UV systems were used, and 2018, when the UV systems were used. RESULTS: The overall incidence of URIs in 2016 was 12.4 cases/100 kitten admissions and in 2018 was 1.6 cases/100 kitten admissions, a significant decrease of 87.1% between the years. CONCLUSIONS AND CLINICAL RELEVANCE: A significant reduction in the incidence of URIs in kittens in a nursery was noted when the UV germicidal irradiation systems were used. Therefore, airborne transmission of feline respiratory pathogens may be more important than has been previously recognized. Ultraviolet germicidal irradiation systems that disinfect the air may be an effective adjunct to standard infection prevention and control protocols in reducing the risk of the transmission of respiratory pathogens among kittens in nurseries and shelters. However, additional studies are needed to confirm the findings reported here.


Asunto(s)
Enfermedades de los Gatos , Infecciones del Sistema Respiratorio , Animales , Enfermedades de los Gatos/epidemiología , Enfermedades de los Gatos/prevención & control , Gatos , Desinfección , Femenino , Incidencia , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/prevención & control , Infecciones del Sistema Respiratorio/veterinaria , Rayos Ultravioleta/efectos adversos , Ventilación
8.
Am J Vet Res ; 81(6): 506-513, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32436797

RESUMEN

OBJECTIVE: To determine whether exposure to UV germicidal irradiation (UVGI) reduces concentrations of viable aerosolized microorganisms (attenuated strains of common veterinary pathogens) in a simulated heating, ventilation, and air conditioning (HVAC) system. SAMPLE: 42 air samples seeded with bacteriophage MS2 or attenuated strains of Bordetella bronchiseptica, feline calicivirus, feline herpesvirus-1, canine parvovirus, or canine distemper virus (6/microorganism) or with no microorganisms added (6). PROCEDURES: A simulated HVAC unit was built that included a nebulizer to aerosolize microorganisms suspended in phosphate-buffered water, a fan to produce airflow, 2 UVGI bulb systems, and an impinger for air sampling. Ten-minute trials (3 with UVGI, 3 without UVGI, and 1 negative control) were conducted for each microorganism. Impingers collected microorganisms into phosphate-buffered water for subsequent quantification with culture-based assays. Results for samples yielding no target microorganisms were recorded as the assay's lower limit of detection. Statistical analysis was not performed. RESULTS: The UVGI treatment resulted in subjectively lower concentrations of viable MS2, B bronchiseptica, and canine distemper virus (arithmetic mean ± SD log10 microorganism reduction, 2.57 ± 0.47, ≥ 3.45 ± 0.24, and ≥ 1.50 ± 0.25, respectively) collected from air. Feline herpesvirus-1 was detected in only 1 sample without and no samples with UVGI treatment. Feline calicivirus and canine parvovirus were not detectable in any collected samples. CONCLUSIONS AND CLINICAL RELEVANCE: Results for some surrogates of veterinary pathogens suggested a potential benefit to supplementing manual disinfection practices with UVGI-based air cleaning systems in animal care environments. Further research is needed to investigate the utility of UVGI in operating HVAC systems.


Asunto(s)
Microbiología del Aire , Rayos Ultravioleta , Animales , Gatos , Desinfección , Ventilación
9.
Arch Virol ; 154(4): 555-60, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19253013

RESUMEN

Feline calicivirus (FCV) is a common cause of upper respiratory tract disease in cats and is associated with interstitial pneumonia, oral ulceration and polyarthritis. Recently, outbreaks have involved a highly virulent FCV that leads to multisystemic signs. Virus isolation and conventional RT-PCR are the most common methods used for FCV diagnosis. However, real-time RT-PCR offers a rapid, sensitive, specific and easy tool for nucleic acid detection. The objective of this study was to design a TaqMan probe-based, real-time RT-PCR assay for detection of FCV. It was determined in our previous study that the first 120 nucleotides of the 5' region of the genome are highly conserved among FCV isolates. Primers and a probe specific for this region were designed for a real-time RT-PCR assay to detect FCV. Initial validation was done using 15 genetically diverse isolates. Also, 122 samples were tested by the new assay and virus isolation. The real-time RT-PCR assay was as sensitive and specific as virus isolation and was far more rapid. This real-time RT-PCR assay targeting the conserved 5' region of the genome is a fast, economical and accurate method for detection of FCV.


Asunto(s)
Infecciones por Caliciviridae/veterinaria , Calicivirus Felino/aislamiento & purificación , Enfermedades de los Gatos/diagnóstico , Enfermedades de los Gatos/virología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Animales , Infecciones por Caliciviridae/diagnóstico , Proteínas de la Cápside/genética , Gatos , Secuencia Conservada , Cartilla de ADN/genética , Filogenia , ARN Viral/genética , Sensibilidad y Especificidad , Homología de Secuencia de Aminoácido , Factores de Tiempo
10.
Vet Ther ; 10(4): E1-6, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-20425728

RESUMEN

Feline panleukopenia virus (FPV) is a significant pathogen of cats. Rapid virus detection is critical for treatment and management, especially in populations in which spread may occur. This study investigated the ability of the SNAP Canine Parvovirus Antigen Test Kit (SNAP Parvo, IDEXX Laboratories) to detect FPV with confirmation of viral identity by polymerase chain reaction (PCR) assay and genetic sequencing on fecal samples (n = 97) from cats with suspected FPV infection. Fifty-five samples were positive by SNAP Parvo; 54 of 55 were also positive by conventional PCR assay and were identified as FPV by genetic sequencing. This study demonstrates that SNAP Parvo can detect FPV in clinical samples.


Asunto(s)
Ensayo de Inmunoadsorción Enzimática/veterinaria , Virus de la Panleucopenia Felina/aislamiento & purificación , Panleucopenia Felina/virología , Parvovirus/aislamiento & purificación , Animales , Gatos , Perros , Ensayo de Inmunoadsorción Enzimática/métodos , Heces/virología , Panleucopenia Felina/diagnóstico , Virus de la Panleucopenia Felina/genética , Reacción en Cadena de la Polimerasa/veterinaria
11.
Am J Vet Res ; 69(9): 1179-82, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18764691

RESUMEN

OBJECTIVE: To determine whether expression of feline coronavirus (FCoV) 7b protein, as indicated by the presence of specific serum antibodies, consistently correlated with occurrence of feline infectious peritonitis (FIP) in cats. SAMPLE POPULATION: 95 serum samples submitted for various diagnostic assays and 20 samples from specific-pathogen-free cats tested as negative control samples. PROCEDURES: The 7b gene from a virulent strain of FCoV was cloned into a protein expression vector. The resultant recombinant protein was produced and used in antibody detection assays via western blot analysis of serum samples. Results were compared with those of an immunofluorescence assay (IFA) for FCoV-specific antibody and correlated with health status. RESULTS: Healthy IFA-seronegative cats were seronegative for antibodies against the 7b protein. Some healthy cats with detectable FCoV-specific antibodies as determined via IFA were seronegative for antibodies against the 7b protein. Serum from cats with FIP had antibodies against the 7b protein, including cats with negative results via conventional IFA. However, some healthy cats, as well as cats with conditions other than FIP that were seropositive to FCoV via IFA, were also seropositive for the 7b protein. CONCLUSIONS AND CLINICAL RELEVANCE: Expression of the 7b protein, as indicated by detection of antibodies against the protein, was found in most FCoV-infected cats. Seropositivity for this protein was not specific for the FCoV virulent biotype or a diagnosis of FIP.


Asunto(s)
Anticuerpos Antivirales/análisis , Coronavirus Felino/inmunología , Peritonitis Infecciosa Felina/diagnóstico , Peritonitis Infecciosa Felina/inmunología , Proteínas Virales/inmunología , Animales , Anticuerpos Antivirales/inmunología , Western Blotting , Gatos , Peritonitis Infecciosa Felina/virología , Técnica del Anticuerpo Fluorescente Indirecta , Sensibilidad y Especificidad
12.
Am J Vet Res ; 67(4): 627-32, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16579755

RESUMEN

OBJECTIVE: To analyze the 7a7b genes of the feline coronavirus (FCoV) of cheetahs, which are believed to play a role in virulence of this virus. SAMPLE POPULATION: Biologic samples collected during a 4-year period from 5 cheetahs at the same institution and at 1 time point from 4 cheetahs at different institutions. PROCEDURES: Samples were first screened for FCoV via a reverse transcription-PCR procedure involving primers that encompassed the 3'-untranslated region. Samples that yielded positive assay results were analyzed by use of primers that targeted the 7a7b open reading frames. The nucleotide sequences of the 7a7b amplification products were determined and analyzed. RESULTS: In most isolates, substantial deletional mutations in the 7a gene were detected that would result in aberrant or no expression of the 7a product because of altered reading frames. Although the 7b gene was also found to contain mutations, these were primarily point mutations resulting in minor amino acid changes. The coronavirus associated with 1 cheetah with feline infectious peritonitis had intact 7a and 7b genes. CONCLUSIONS AND CLINICAL RELEVANCE: The data suggest that mutations arise readily in the 7a region and may remain stable in FCoV of cheetahs. In contrast, an intact 7b gene may be necessary for in vivo virus infection and replication. Persistent infection with FCoV in a cheetah population results in continued virus circulation and may lead to a quasispecies of virus variants.


Asunto(s)
Acinonyx/virología , Coronavirus/genética , Mutación , Sistemas de Lectura Abierta , Secuencia de Aminoácidos , Animales , Secuencia Conservada , Coronavirus/clasificación , Coronavirus/aislamiento & purificación , Filogenia , Mutación Puntual , ARN Viral/genética , ARN Viral/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Alineación de Secuencia , Eliminación de Secuencia , Homología de Secuencia de Aminoácido , Proteínas Virales/química , Proteínas Virales/genética
13.
Genome Announc ; 3(6)2015 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-26701085

RESUMEN

Here, we report the complete genome sequence of bovine viral diarrhea virus-1b (BVDV-1b), strain Egy/Ismailia/2014. The virus genome is composed of 12,217 nucleotides organized as one open reading frame encoding 3,898 amino acids. This report will assist efforts in diagnostics, studying molecular epidemiology, and control of BVDV in Egypt.

14.
J Infect Dev Ctries ; 9(12): 1331-7, 2015 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-26719939

RESUMEN

INTRODUCTION: Bovine viral diarrhea (BVD) is one of the most economically significant diseases in the bovine industry causing losses due to diarrhea, reproductive disorders, immunosuppression and mortalities. The aim of our investigation was to detect and subtype BVDV from calves on two dairy cattle and two buffalo farms in Ismailia province, Egypt as an indicator of BVDV infection status in the province. METHODOLOGY: A total of 298 blood samples were collected and tested using an optimized one-step, real-time multiplex Taqman-based RT-PCR. All the positive samples by the multiplex real-time RT-PCR were tested using conventional RT-PCR to amplify multiple areas of the genome for further phylogenetic analysis and subtyping. RESULTS: Thirty one (10.4%) of the tested samples were positive for BVDV-1. Only three samples, all from a single dairy cattle farm, had enough viral RNA to be amplified by RT-PCR. The PCR products were sequenced and phylogenetic analysis revealed detection of BVDV-1b. The detected strain is closely related to worldwide BVDV-1b strains, making it difficult to trace its origin. Nucleotide and amino acid alignments of the E2 glycoprotein region of the detected strain with other BVDV-1b strains showed high divergence, with identity ranging from 81.3% to 93.6% and 85.3% to 93.6%, respectively. CONCLUSION: To our knowledge, this is the first report describing the circulation of BVDV-1b in Egyptian dairy cattle populations.


Asunto(s)
Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/virología , Virus de la Diarrea Viral Bovina Tipo 1/clasificación , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Genotipo , Infecciones por Pestivirus/veterinaria , Agricultura , Animales , Sangre/virología , Búfalos , Bovinos , Virus de la Diarrea Viral Bovina Tipo 1/genética , Egipto/epidemiología , Técnicas de Genotipaje , Epidemiología Molecular , Reacción en Cadena de la Polimerasa Multiplex , Infecciones por Pestivirus/epidemiología , Infecciones por Pestivirus/virología , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
15.
Exp Gerontol ; 38(9): 997-1008, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12954487

RESUMEN

Ames dwarf mice live 50-64% longer and exhibit upregulated antioxidative defenses and lower cellular damage when compared to age-matched wild-type littermates. Due to the relationship between aging and apoptosis, the purpose of this study was to compare basal levels of apoptosis-related proteins in dwarf and wild-type tissues and to compare the response of dwarf and wild-type primary hepatocytes to oxidative stress. Hepatocytes from dwarf and wild-type mice (6 month-old) were isolated using collagenase perfusion and treated with hydrogen peroxide. Viability, activity, protein levels, and morphological changes were evaluated. Procaspase-3 protein levels were increased in dwarf kidney and liver (p<0.05) while Bcl-2 protein levels were significantly higher in dwarf liver at 24 months of age. Bax protein levels were markedly elevated in several tissues at different ages and Bcl-2/Bax ratios were lower in many dwarf tissues. In culture, peroxide-treated dwarf hepatocytes showed lower viability (p<0.03) and higher caspase-3 activity induction when compared to peroxide-treated wild-type cells. Peroxide-treated dwarf hepatocytes frequently showed morphological characteristics reminiscent of apoptosis, which were not observed in peroxide-treated wild-type hepatocytes. This suggests that when experiencing an oxidative challenge, Ames dwarf hepatocytes more readily undergo apoptosis than wild-type cells, providing an advantage to dwarf mice, whereby they more efficiently eliminate damaged cells, thus contributing to their longer lives.


Asunto(s)
Envejecimiento/patología , Apoptosis/fisiología , Enanismo/patología , Hepatocitos/ultraestructura , Longevidad/fisiología , Envejecimiento/genética , Envejecimiento/fisiología , Animales , Caspasa 3 , Caspasas/metabolismo , Células Cultivadas , Citocromos c/metabolismo , Enanismo/genética , Enanismo/metabolismo , Precursores Enzimáticos/metabolismo , Hígado/enzimología , Hígado/metabolismo , Ratones , Ratones Mutantes , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteína X Asociada a bcl-2
16.
Exp Biol Med (Maywood) ; 227(2): 94-104, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11815672

RESUMEN

The physiological decline that occurs in aging is thought to result, in part, from accumulation of oxidative damage generated by reactive oxygen species during normal metabolic processes. Elevated levels of antioxidative enzymes in liver tissues are present in the Ames dwarf, a growth hormone (GH)-deficient mouse that lives more than 1 year longer than wild-type mice from the same line. In contrast, transgenic mice that overexpress GH exhibit depressed hepatic levels of catalase and have significantly shortened life spans. In this study, we evaluated the in vitro effects of GH and insulin-like growth factor 1 (IGF-1) on antioxidative enzymes in mouse hepatocytes. Hepatocytes were isolated from wild-type mice following perfusion of livers with a collagenase-based buffer. Dispersed cells were plated on Matrigel and treated with rat GH (0.1, 1.0, or 10 microg/ml) or IGF-1 (0.5, 5.0, or 50 nM) for 24 hr. Hepatocytes were recovered and protein was extracted for immunoblotting and enzyme activity assays of catalase (CAT), glutathione peroxidase (GPX), and manganese superoxide dismutase (MnSOD). A 41% and 27% decrease in catalase activity was detected in cells treated with GH, whereas IGF-1 reduced CAT activity levels to a greater extent than GH (P < 0.0001). The activity and protein levels of GPX were also significantly depressed in cells treated with GH, whereas activity alone was decreased in cells treated with IGF-1 (P < 0.04). GH significantly suppressed MnSOD levels by 40% and 66% in 1.0 and 0.1 microg/ml concentrations, respectively. Similarly, IGF-1 decreased MnSOD protein levels (5 nM; P < 0.05). These results suggest that GH and IGF-1 may decrease the ability of hepatocytes to counter oxidative stress. In addition, these experiments provide an explanation for the differing antioxidative defense capacity of GH-deficient versus GH-overexpressing mice, and they suggest that GH is directly involved in antioxidant regulation and the aging process.


Asunto(s)
Catalasa/metabolismo , Glutatión Peroxidasa/metabolismo , Hormona del Crecimiento/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Hígado/enzimología , Superóxido Dismutasa/metabolismo , Envejecimiento/metabolismo , Animales , Catalasa/análisis , Células Cultivadas , Femenino , Glutatión Peroxidasa/análisis , Hormona del Crecimiento/farmacología , Factor I del Crecimiento Similar a la Insulina/farmacología , Masculino , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , Superóxido Dismutasa/análisis
17.
J Am Vet Med Assoc ; 225(5): 726-31, 2004 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-15457667

RESUMEN

OBJECTIVE: To measure antibody titers against bovine coronavirus (BCV), determine frequency of BCV in nasal swab specimens, and compare calves treated for bovine respiratory tract disease (BRD) between those given an intranasally administered vaccine and control calves. DESIGN: Randomized clinical trial. ANIMALS: 414 heifer calves. PROCEDURE: Intranasal BCV antigen concentration and antibody titer against BCV were measured on entry to a feedlot. Calves were randomly assigned to receive 3.0 mL of a modified-live virus vaccine against bovine enteric coronavirus and rotavirus or 3.0 mL of saline (0.9% NaCl) solution. Calves were confined to 1 of 2 pens, depending on vaccination status, for a minimum of 17 days of observation (range, 17 to 99). Selection of calves for treatment of BRD and scoring for severity of disease were done by veterinarians unaware of treatment status. RESULTS: Intranasal BCV (125/407 [31%]) and serum antibody titers > or = 20 against BCV (246/396 [62%]) were identified in calves entering the feedlot. Vaccination was associated with significant decrease in risk of treatment for BRD; intranasal BCV on entry to the feedlot was associated with increased risk of treatment. Univariate analysis revealed that control calves with intranasal BRD on entry to the feedlot and those with antibody titer < 20 were significantly more likely to be treated for BRD. CONCLUSIONS AND CLINICAL RELEVANCE: These data provide further evidence of an association between BCV and respiratory tract disease in feedlot calves. An intranasally administered vaccine appeared to reduce risk of treatment for BRD.


Asunto(s)
Enfermedades de los Bovinos/prevención & control , Infecciones por Coronavirus/veterinaria , Coronavirus Bovino/inmunología , Infecciones del Sistema Respiratorio/veterinaria , Vacunas Virales/administración & dosificación , Administración Intranasal , Animales , Anticuerpos Antivirales/sangre , Bovinos , Enfermedades de los Bovinos/epidemiología , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/prevención & control , Femenino , Cavidad Nasal/virología , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/prevención & control , Factores de Riesgo , Vacunas Atenuadas/administración & dosificación
18.
J Vet Diagn Invest ; 26(1): 27-34, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24532693

RESUMEN

Canine distemper virus (CDV) remains a common cause of infectious disease in dogs, particularly in high-density housing situations such as shelters. Vaccination of all dogs against CDV is recommended at the time of admission to animal shelters and many use a modified live virus (MLV) vaccine. From a diagnostic standpoint for dogs with suspected CDV infection, this is problematic because highly sensitive diagnostic real-time reverse transcription polymerase chain reaction (RT-PCR) tests are able to detect MLV virus in clinical samples. Real-time PCR can be used to quantitate amount of virus shedding and can differentiate vaccine strains from wild-type strains when shedding is high. However, differentiation by quantitation is not possible in vaccinated animals during acute infection, when shedding is low and could be mistaken for low level vaccine virus shedding. While there are gel-based RT-PCR assays for differentiation of vaccine strains from field strains based on sequence differences, the sensitivity of these assays is unable to match that of the real-time RT-PCR assay currently used in the authors' laboratory. Therefore, a real-time RT-PCR assay was developed that detects CDV MLV vaccine strains and distinguishes them from wild-type strains based on nucleotide sequence differences, rather than the amount of viral RNA in the sample. The test is highly sensitive, with detection of as few as 5 virus genomic copies (corresponding to 10(-1) TCID(50)). Sequencing of the DNA real-time products also allows phylogenetic differentiation of the wild-type strains. This test will aid diagnosis during outbreaks of CDV in recently vaccinated animals.


Asunto(s)
Brotes de Enfermedades/veterinaria , Virus del Moquillo Canino/aislamiento & purificación , Moquillo/virología , Enfermedades de los Perros/virología , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Vacunas Virales/genética , Animales , Secuencia de Bases , Moquillo/sangre , Virus del Moquillo Canino/genética , Enfermedades de los Perros/sangre , Perros , Datos de Secuencia Molecular , Filogenia , ARN Viral/química , ARN Viral/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/normas , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Alineación de Secuencia , Análisis de Secuencia de ADN , Vacunas Atenuadas/genética , Proteínas de la Matriz Viral/química , Proteínas de la Matriz Viral/genética
19.
Am J Vet Res ; 75(9): 828-34, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25157886

RESUMEN

OBJECTIVE: To evaluate the ability of small interfering RNAs (siRNAs) to inhibit in vitro viral replication and gene expression of feline coronavirus (FCoV). SAMPLE: Cell cultures of Crandell-Rees feline kidney cells. PROCEDURES: 5 synthetic siRNAs that each targeted a different region of the FCoV genome were tested individually and in various combinations for their antiviral effects against 2 strains of FCoV (feline infectious peritonitis virus WSU 79-1146 and feline enteric coronavirus WSU 79-1683) in cell cultures. Tested combinations targeted the FCoV leader and 3' untranslated region, FCoV leader region and nucleocapsid gene, and FCoV leader region, 3' untranslated region, and nucleocapsid gene. For each test condition, assessments included relative quantification of the inhibition of intracellular viral genomic RNA synthesis by means of real-time, reverse-transcription PCR analysis; flow cytometric evaluation of the reduction of viral protein expression in infected cells; and assessment of virus replication inhibition via titration of extracellular virus with a TCID50 infectivity assay. RESULTS: The 5 siRNAs had variable inhibitory effects on FCoV when used singly. Combinations of siRNAs that targeted different regions of the viral genome resulted in more effective viral inhibition than did individual siRNAs that targeted a single gene. The tested siRNA combinations resulted in approximately 95% reduction in viral replication (based on virus titration results), compared with findings in negative control, nontargeting siRNA-treated, FCoV-infected cells. CONCLUSIONS AND CLINICAL RELEVANCE: In vitro replication of FCoV was specifically inhibited by siRNAs that targeted coding and noncoding regions of the viral genome, suggesting a potential therapeutic application of RNA interference in treatment of feline infectious peritonitis.


Asunto(s)
Coronavirus Felino/fisiología , Regulación Viral de la Expresión Génica/fisiología , ARN Interferente Pequeño/fisiología , Replicación Viral/fisiología , Animales , Gatos , Línea Celular , Genoma Viral , ARN Interferente Pequeño/genética , ARN Viral/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Proteínas Virales/genética , Cultivo de Virus
20.
J S Afr Vet Assoc ; 85(1): 1110, 2014 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-25686382

RESUMEN

Domestic dogs are common amongst communities in sub-Saharan Africa and may serve as important reservoirs for infectious agents that may cause diseases in wildlife. Two agents of concern are canine parvovirus (CPV) and canine distemper virus (CDV), which may infect and cause disease in large carnivore species such as African wild dogs and African lions, respectively. The impact of domestic dogs and their diseases on wildlife conservation is increasing in Zimbabwe, necessitating thorough assessment and implementation of control measures. In this study, domestic dogs in north-western Zimbabwe were evaluated for antibodies to CDV, CPV, and canine adenovirus (CAV). These dogs were communal and had no vaccination history. Two hundred and twenty-five blood samples were collected and tested using a commercial enzyme-linked immunosorbent assay (ELISA) for antibodies to CPV, CDV, and CAV. Of these dogs, 75 (34%) had detectable antibodies to CDV, whilst 191 (84%) had antibodies to CPV. Antibodies to canine adenovirus were present in 28 (13%) dogs. Canine parvovirus had high prevalence in all six geographic areas tested. These results indicate that CPV is circulating widely amongst domestic dogs in the region. In addition, CDV is present at high levels. Both pathogens can infect wildlife species. Efforts for conservation of large carnivores in Zimbabwe must address the role of domestic dogs in disease transmission.


Asunto(s)
Adenovirus Caninos/aislamiento & purificación , Virus del Moquillo Canino/aislamiento & purificación , Moquillo/sangre , Enfermedades de los Perros/sangre , Infecciones por Parvoviridae/veterinaria , Parvovirus Canino/aislamiento & purificación , Infecciones por Adenoviridae/sangre , Infecciones por Adenoviridae/epidemiología , Infecciones por Adenoviridae/veterinaria , Infecciones por Adenoviridae/virología , Animales , Anticuerpos Antivirales/sangre , Moquillo/epidemiología , Moquillo/virología , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/epidemiología , Perros , Femenino , Masculino , Infecciones por Parvoviridae/sangre , Infecciones por Parvoviridae/epidemiología , Infecciones por Parvoviridae/virología , Prevalencia , Zimbabwe/epidemiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA