Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Distemper”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,405 records · Page 78Linked to original sources

Measles virus haemagglutinin induces down-regulation of gp57/67, a molecule involved in virus binding.

A surface glycoprotein (gp57/67) was previously shown to be involved in measles virus (MV) binding and characterized in our laboratory. Here, we described down-regulation of cell surface gp57/67 after infection with MV. This effect is specific for MV since cells infected with canine distemper virus, closely related to MV, did not down-regulate gp57/67. The decrease in cell surface gp57/67 correlated with expression of MV glycoproteins and more particularly with the expression of MV haemagglutinin (MV-H). Indeed, expression of MV-H after infection with a vaccinia virus recombinant coding for MV-H was necessary and sufficient to induce down-regulation of gp57/67. Kinetics of cell surface expression of MV-H and gp57/67 showed that the degree of down-regulation was correlated with the amount of MV-H expressed by infected cells. Experiments using antibody-prelabelled gp57/67 and indirect immunofluorescence microscopy allowed us to follow the fate of gp57/67 and showed that down-regulation was occurring by rapid internalization of gp57/67 from the cell surface. These results provide additional evidence that the gp57/67 molecule is closely associated with the pathway of MV infection and also reveal a phenomenon which may be related to viral pathogenesis and persistence.

Biological Transport↗

Sequencing and analysis of the nucleocapsid (N) and polymerase (L) genes and the terminal extragenic domains of the vaccine strain of rinderpest virus.

The nucleocapsid (N) and polymerase (L) genes of the vaccine strain of rinderpest, and the 5' and 3' terminal domains of the genome have been sequenced. Together with previously published data, this completes the sequence of the entire genome of rinderpest virus. The viral genome is 15,881 bases in length, similar to that of measles virus and slightly longer than that of canine distemper virus. The L gene is identical in length to that of measles virus, encoding a 2183 amino acid protein with a calculated M(r) of 248,100. The L protein sequence of morbilliviruses is highly conserved, more than 75% of residues being identical or conserved in all three sequences currently available. The N protein was, as for the other sequenced genes where comparison is possible, essentially identical to that of the virulent parent. In addition, we have determined the terminal sequences of two virulent strains of rinderpest and compared the sequences of virulent and non-virulent strains.

Amino Acid Sequence↗

Histidine at position 61 and its adjacent amino acid residues are critical for the ability of SLAM (CD150) to act as a cellular receptor for measles virus.

Signalling lymphocyte activation molecule (SLAM, also known as CD150), a membrane glycoprotein involved in lymphocyte activation, has two extracellular immunoglobulin superfamily domains, V and C2. It has been shown previously that human SLAM is a cellular receptor for measles virus (MV) and that its V domain is necessary and sufficient for receptor function. Although mouse SLAM has functional and structural similarity to human SLAM, it hardly acts as a receptor for MV. By producing human/mouse chimeric molecules and assessing their receptor function with a vesicular stomatitis virus pseudotype assay, the region at amino acid positions 58-67 was found to be critically responsible for the difference in MV receptor function between human and mouse SLAMs. Exchange of this region allowed mouse SLAM to act as a receptor for MV, almost comparable to human SLAM. Among three amino acid differences (positions 60, 61 and 63) in this region, histidine 61 present in human SLAM was most significant, but combined substitutions with this residue and one or both of isoleucine 60 and valine 63 increased further the receptor activity of mouse SLAM. On the other hand, converse substitution at position 61 compromised receptor function of human SLAM. Thus, histidine 61 and its adjacent residues at positions 60 and 63 are critical for SLAM to act as a receptor for MV. Notably, the pseudotype assay indicated that residues at these three positions are also critical for the function of SLAM as a receptor for canine distemper virus.

Animals↗

Phylogenetic analysis reveals a low rate of homologous recombination in negative-sense RNA viruses.

Recombination is increasingly seen as an important means of shaping genetic diversity in RNA viruses. However, observed recombination frequencies vary widely among those viruses studied to date, with only sporadic occurrences reported in RNA viruses with negative-sense genomes. To determine the extent of homologous recombination in negative-sense RNA viruses, phylogenetic analyses of 79 gene sequence alignments from 35 negative-sense RNA viruses (a total of 2154 sequences) were carried out. Powerful evidence was found for recombination, in the form of incongruent phylogenetic trees between different gene regions, in only five sequences from Hantaan virus, Mumps virus and Newcastle disease virus. This is the first report of recombination in these viruses. More tentative evidence for recombination, where conflicting phylogenetic trees were observed (but were without strong bootstrap support) and/or where putative recombinant regions were very short, was found in three alignments from La Crosse virus and Puumala virus. Finally, patterns of sequence variation compatible with the action of recombination, but not definitive evidence for this process, were observed in a further ten viruses: Canine distemper virus, Crimean-Congo haemorrhagic fever virus, Influenza A virus, Influenza B virus, Influenza C virus, Lassa virus, Pirital virus, Rabies virus, Rift Valley Fever virus and Vesicular stomatitis virus. The possibility of recombination in these viruses should be investigated further. Overall, this study reveals that rates of homologous recombination in negative-sense RNA viruses are very much lower than those of mutation, with many viruses seemingly clonal on current data. Consequently, recombination rate is unlikely to be a trait that is set by natural selection to create advantageous or purge deleterious mutations.

Animals↗

Measles virus superinfection immunity and receptor redistribution in persistently infected NT2 cells.

A recombinant measles virus (MV) expressing red fluorescent protein (MVDsRed1) was used to produce a persistently infected cell line (piNT2-MVDsRed1) from human neural precursor (NT2) cells. A similar cell line (piNT2-MVeGFP) was generated using a virus that expresses enhanced green fluorescent protein. Intracytoplasmic inclusions containing the viral nucleocapsid protein were evident in all cells and viral glycoproteins were present at the cell surface. Nevertheless, the cells did not release infectious virus nor did they fuse to generate syncytia. Uninfected NT2 cells express the MV receptor CD46 uniformly over their surface, whereas CD46 was present in cell surface aggregates in the piNT2 cells. There was no decrease in the overall amount of CD46 in piNT2 compared to NT2 cells. Cell-to-cell fusion was observed when piNT2 cells were overlaid onto confluent monolayers of MV receptor-positive cells, indicating that the viral glycoproteins were correctly folded and processed. Infectious virus was released from the underlying cells, indicating that persistence was not due to gross mutations in the virus genome. Persistently infected cells were superinfected with MV or canine distemper virus and cytopathic effects were not observed. However, mumps virus could readily infect the cells, indicating that superinfection immunity is not caused by general soluble antiviral factors. As MVeGFP and MVDsRed1 are antigenically indistinguishable but phenotypically distinct it was possible to use them to measure the degree of superinfection immunity in the absence of any cytopathic effect. Only small numbers of non-fusing green fluorescent piNT2-MVDsRed1 cells (1 : 300 000) were identified in which superinfecting MVeGFP entered, replicated and expressed its genes.

Antigens, CD↗

Measles virus: cellular receptors, tropism and pathogenesis.

Measles virus (MV), a member of the genus Morbillivirus in the family Paramyxoviridae, is an enveloped virus with a non-segmented, negative-strand RNA genome. It has two envelope glycoproteins, the haemagglutinin (H) and fusion proteins, which are responsible for attachment and membrane fusion, respectively. Human signalling lymphocyte activation molecule (SLAM; also called CD150), a membrane glycoprotein of the immunoglobulin superfamily, acts as a cellular receptor for MV. SLAM is expressed on immature thymocytes, activated lymphocytes, macrophages and dendritic cells and regulates production of interleukin (IL)-4 and IL-13 by CD4+ T cells, as well as production of IL-12, tumour necrosis factor alpha and nitric oxide by macrophages. The distribution of SLAM is in accord with the lymphotropism and immunosuppressive nature of MV. Canine distemper virus and Rinderpest virus, other members of the genus Morbillivirus, also use canine and bovine SLAM as receptors, respectively. Laboratory-adapted MV strains may use the ubiquitously expressed CD46, a complement-regulatory molecule, as an alternative receptor through amino acid substitutions in the H protein. Furthermore, MV can infect SLAM- cells, albeit inefficiently, via the SLAM- and CD46-independent pathway, which may account for MV infection of epithelial, endothelial and neuronal cells in vivo. MV infection, however, is not determined entirely by the H protein-receptor interaction, and other MV proteins can also contribute to its efficient growth by facilitating virus replication at post-entry steps. Identification of SLAM as the principal receptor for MV has provided us with an important clue for better understanding of MV tropism and pathogenesis.

Humans↗

Production of a new model of slowly progressive Heymann nephritis.

A slowly progressive autoimmune kidney disease was induced in Sprague Dawley rats by subcutaneous injection of a chemically modified kidney antigen (rKF3), incorporated into Alum and Distemper complex vaccine, followed by subcutaneous injections of an aqueous preparation of the same antigen. Pathogenic autoantibodies developed, which reacted with fixed glomerular nephritogenic antigen. Subsequently, immunopathological events lead to chronic progressive immune complex glomerulonephritis and proteinuria. The slowly developing disease was morphologically and functionally similar to Heymann nephritis (HN). The damage observed in the kidneys of experimental animals at 8 weeks and at the end of the experiment was examined by direct fluorescent antibody test, histology and electron microscopy. The changes were similar to the typical lesions found in HN rat kidneys, but less severe. Animals became proteinuric from 17 weeks onward (instead of the usual 4-8 weeks). By the end of the experiment, at 8 months, 100% of the rats were proteinuric. This new experimental model of autoimmune kidney disease, which is not complicated by intraperitoneal deposition and retention of Freund's complete adjuvant and renal tubular antigens, allowed us to investigate the pathogenesis of the disease processes from a different aspect, and promises to be a useful and improved model for the investigation of future treatment options.

Animals↗

The morbillivirus receptor SLAM (CD150).

Morbilliviruses are highly contagious pathogens that cause some of the most devastating viral diseases of humans and animals, including measles virus (MV), canine distemper virus (CDV), and rinderpest virus (RPV). They replicate mainly in lymphoid organs throughout the body and cause severe immunosuppression accompanied with lymphopenia. We have recently shown that human, canine, and bovine signaling lymphocyte activation molecules (SLAMs; also known as CD150) act as cellular receptors for MV, CDV, and RPV, respectively. In these three morbilliviruses, all strains examined were shown to use SLAMs of their respective host species, and laboratory strains passaged on SLAM-negative cells were found to use, besides SLAM, alternative receptors, such as human CD46 for the Edmonston strain of MV. The use of SLAM as a receptor may be a property common to most, if not all, of the members of morbilliviruses. Human SLAM is a membrane glycoprotein selectively expressed on the cells of the immune system (immature thymocytes, activated lymphocytes, activated monocytes, and mature dendritic cells) and seems to mediate lymphocyte activation and to control interferon-gamma production. The destruction and/or impairment of infected SLAM-positive cells may be a mechanism for the immunosuppression induced by morbilliviruses, but other mechanisms may be also involved.

Amino Acid Sequence↗

Light and electron microscopical studies of the immunoperoxidase staining of multiple sclerosis plaques using antisera to a feline-derived agent and to galactocerebroside.

Antibodies have been raised to two agents (CCA147 and MV631) that were isolated from central nervous tissue of cats. The cells co-cultivated with these agents are characterized by the presence of cytoplasmic inclusions consisting of 16-18 nm diameter tubular elements morphologically similar to inclusions seen in a demyelinating condition in cats and to inclusions described as 'curved linear profiles' in multiple sclerosis (MS) plaques. The peroxidase-labelled antibodies to CCA147 and MV631 stain these inclusions in MS plaques as well as small virus-like particles. The antisera do not stain normal white matter either in MS or non-MS brain tissue. The staining reaction of one agent is blocked by pretreatment with antisera to the other agent and also by pretreatment with MS sera but not by normal human sera. Peroxidase-labelled antibody to galactocerebroside stains normal myelin and myelin debris within MS plaques but does not stain the 'curved linear profiles' that are stained by the labelled antibodies to the feline-derived agents. The results show that the 'curved linear profiles' described in MS plaques are not myelin degradation products, but are comparable to the nucleocapsids of morbilliviruses. In addition, the small virus-like particles are morphologically similar to morbillivirus virions. The results are discussed with particular emphasis on the features of the morbilliviruses, canine distemper and measles viruses.

Animals↗

The possible enhancement of parvovirus vaccination on the mortality rate of diseased dogs.

A survey was conducted by using questionnaires dealing with morbidity and mortality of young dogs. Seventy-one clinical evaluations of diseased dogs were included in this survey. The cases were divided into 3 groups according to their vaccination history: 1. dogs vaccinated with the parvovirus and distemper live modified vaccine; 2. dogs vaccinated with the killed parvovirus vaccine; 3. non-vaccinated dogs. Statistical analysis of the information obtained by analyzing the questionnaires gave the following results: The survival rate of the non-vaccinated and killed parvovirus vaccine-vaccinated dogs was significantly higher than that of the dogs which were vaccinated by the live modified vaccine. No such difference was encountered between groups 2 and 3. This finding, once more, supports the notion that the live modified parvovirus vaccine may have an immunosuppressive property.

Animals↗

Morbillivirus infection of seals (Phoca vitulina) during the 1988 epidemic in the Bay of Heligoland. I. Mode, frequency and significance of cultural virus isolation and neutralizing antibody detection.

From 16 (14%) out of 112 dead or euthanized seals originating from wildlife and seal orphanages phocine morbillivirus was isolated. The majority of viral isolates in cell cultures was obtained from lung homogenates of 15 out of 71 free-ranging seals (21%). The virus was isolated by longterm cultivation in roller cultures of seal kidney cells. The phocine morbillivirus was detected by typical cytopathogenic alteration and by peroxidase-linked antibody (PLA) assay, respectively. A neutralization test based on PLA was used for antibody detection in seals using a canine distemper virus (CDV) strain and in parallel one of the phocine morbillivirus isolates. All sera tested were proven to contain neutralizing antibodies of higher titres against the latter virus than against the CDV strain. Several seals furnished morbillivirus isolates and at the same time exhibited neutralizing antibodies of low to medium titres. No viral isolates were obtained from the majority of sick animals with moderate to high neutralizing titres (greater than 1/1,000). The significance of these findings is discussed in relation to the cause of the mass mortality amongst seals observed in 1988 in the Bay of Heligoland.

Animals↗

The production of peste des petits ruminants hyperimmune sera in rabbits and their application in virus diagnosis.

Hyperimmune sera were produced by serial inoculation of rabbits with Vero cell-adapted, sucrose gradient-purified Nigerian peste des petits ruminants virus (PPRV) isolate. Two antisera produced, neutralized the homologous PPRV but not the heterologous rinderpest Kabette "O" virus. The antisera gave strong precipitin lines with purified PPRV antigens and were used to detect PPRV and rinderpest virus antigens from ante-mortem secretions and post-mortem tissue homogenates from PPR and rinderpest virus infected goats and cattle by the agar gel precipitation tests (AGPT). The hyperimmune sera gave good titration curves with both purified Nigerian goat and the United Arab Emirate wildlife PPRV isolates in the indirect enzyme linked immunosorbent assay (ELISA). Results of indirect ELISA showed that although there were some cross reactions with the rinderpest, canine-distemper and measles viruses, at 1:100 dilution, the antisera would give a positive signal with only the homologous PPR virus.

Animals↗

Demography, hunting ecology, and pathogen exposure of domestic dogs in the Isoso of Bolivia.

Disease is increasingly recognized as a threat to the conservation of wildlife, and in many cases the source of disease outbreaks in wild carnivores is the domestic dog. For disease to spill over from a domestic to a wild population, three conditions must be satisfied: susceptibility of the wild species, presence of the disease agent in the domestic population, and contact between the two populations of interest. We investigated the potential for disease spillover from the domestic dog population to the wild carnivore population in the Isoso of Bolivia, an area of tropical dry forest contiguous with a national park. Using questionnaires and discussions with residents, we gathered data on the demography of dogs in the Isoso, including adult and neonatal mortality, litter size, and hunting frequency. We analyzed a large data set containing self-recorded information on hunting in various communities of the Isoso to determine the extent of dog participation in hunting and the duration of hunting trips. Finally, we took blood samples from dogs in the Isoso for a serosurvey of common canine pathogens. More than 95% of dogs had positive titers to canine distemper virus and canine parvovirus. There was also a high seroprevalence in dogs for other pathogens, a high population turnover of dogs (which may allow diseases to be maintained endemically), and frequent opportunities for contact between domestic and wild carnivores. Based on our results and the susceptibility of wild species previously reported in the literature, domestic dogs represent a disease risk for wildlife in the Bolivian Isoso.

Animals↗

Melatonin reduces mortality from Aleutian disease in mink (Mustela vison).

Aleutian disease (AD) results from a persistent parvoviral infection that results in marked hypergammaglobulinemia and immune complex mediated lesions of the kidney, liver, lungs and, arteries. Melatonin protected both a wild type or demi strain and a demi/dark crossed strain of mink from AD. The biogenic amine also afforded protection against other non-diagnosed diseases naturally found on mink farms when it was available from a subcutaneously-placed reservoir. Some genetic strains of mink apparently differed in the resistance of mink to the virus and in the protective ability of melatonin. The demi strain was the most resistant followed by pastels, mahogany, darks, and those strains with the double recessive Aleutian gene. The protective action of melatonin appeared to result from melatonin's ability to scavenge free radicals, but it could also be due to the induction of antioxidant enzymes or to the modulation of immunity. Melatonin also protected mink against distemper.

Aleutian Mink Disease↗

Diagnosis of cerebellar cortical degeneration in a Scottish terrier using magnetic resonance imaging.

Primary cerebellar cortical degeneration (CCD), also termed abiotrophy, is the spontaneous premature degeneration of fully differentiated neurological tissue. Cerebellar hypoplasia shares many morphological features with primary CCD, both conditions being characterised by decreased cerebellar size, with reduced numbers of Purkinje and granular cells. CCD has been identified in many canine breeds. This is the first report of the syndrome in a Scottish terrier. The patient presented with mild, gradually progressive ataxia. Survey radiographs of the cervical spine and cerebrospinal fluid (CSF) analysis were normal. CSF distemper and Toxoplasma titres were negative. A diagnosis of cerebellar atrophy was made based on magnetic resonance imaging. The progressive clinical signs suggested cerebellar degeneration rather than hypoplasia. On necropsy, the cerebellum showed macroscopic and microscopic changes consistent with primary CCD.

Animals↗

The isolation of Bordetella bronchiseptic from an outbreak of canine pneumonia.

This report describes an outbreak of bronchitis and bronchopneumonia among young dogs in a breeding kennel following the introduction of two pups from another area. Bordetella bronchiseptica was isolated in heavy culture from affected animals which responded well to antibacterial therapy. There was no evidence of distemper virus involvement. Important bacteriological properties of Bord. bronchiseptica are discussed particularly as they relate to its known pathogenicity in the young of several species of animal. During the outbreak reported, it was noted that only young pups were clinically affected and it is suggested that Bord. bronchiseptica may be pathogenic in a certain age-group within the canine population. This seems to require further investigation.

Animals↗

Juvenile cellulitis in an 8-month-old dog.

An 8-month-old, crossbred dog, presented with a painful, swollen face. The problem was of 4 weeks duration and had not responded to antibiotics. A diagnosis of canine juvenile cellulitis was based on the clinical presentation and supportive cytological and histopathological changes. Attempts to identify canine distemper virus were not successful. Complete resolution occurred with glucocorticoid therapy. This is the first report of canine juvenile cellulitis in a dog of this age.

Age Factors↗

Recent veterinary graduates over the last five decades: initial career experiences.

OBJECTIVE: To describe changes in the initial work experiences of veterinary graduates over the last 50 years. DESIGN: A questionnaire, sent by mail. PROCEDURE: A questionnaire seeking information on work experience as a recent graduate was sent to about 100 veterinarians who graduated in or about each of 1950, 1960, 1970, 1980, 1990 and 2000, and 68% responded. Data were entered onto an Excel spreadsheet, and analysed with the SAS System 8 for Windows. RESULTS: The first veterinary position for about half the graduates of 1950 and 1960 was in government service. Since then an increasing percentage have started in small animal practice; the rest in mixed practice. Many earlier graduates worked alone and for long hours, with little or no respite after hours. Since 1950, the average recent graduate in private practice has worked progressively fewer hours with less after hours duty, and has worked with progressively more other veterinarians. Cattle were almost half the cases seen by graduates of 1950 and 1960. Dogs and cats were about 20% of the cases seen by those graduates, but this percentage ncreased progressively and was 77% of the cases seen by the graduates of 2000. Distemper was the most common transmissible disease of dogs seen by graduates of 1950-1970, but by few since then. Graduates of 1980 saw parvovirus most commonly; those of 2000 saw parvovirus and kennel/canine cough in about equal numbers. Two other major changes in canine cases seen by recent graduates have involved skin conditions, which increased progressively between 1950 and 2000, and trauma, mainly involving vehicles, which decreased as dogs have been restrained more effectively. Fracture repair was the most common surgical procedure performed by recent graduates between 1950 and 1970, but with decreasing incidence of trauma this has been overtaken by the removal of lumps and repair of lacerations. Barbiturates were used extensively by recent graduates for both induction and maintenance of anaesthesia, but with increasing use of anaesthetic machines from 1960 onwards, halothane and more recently isoflurane have largely taken their place for the maintenance of anaesthesia. CONCLUSIONS: Over the last five decades, the average recent graduate has had progressively more opportunity for support and advice from other veterinarians, to work more sociable hours, and to work with a narrower range of species, especially dogs and cats.

Animals↗