Microbiological monitoring in individually ventilated cage systems.

Housing rodents in IVC racks has many advantages over conventional cages but also presents unique challenges related to health monitoring. The authors review the issues to consider in design of a sentinel program using IVC systems.

Efficacy of three microbiological monitoring methods in a ventilated cage rack.

The use of individually ventilated caging (IVC) to house mice presents new challenges for effective microbiological monitoring. Methods that exploit the characteristics of IVC have been developed, but to the authors' knowledge, their efficacy has not been systematically investigated. Air exhausted from the IVC rack can be monitored, using sentinels housed in cages that receive rack exhaust air as their supply air, or using filters placed on the exhaust air port.

Comparison of the sensitivity of in vivo antibody production tests with in vitro PCR-based methods to detect infectious contamination of biological materials.

Bacteria and viruses may be transmitted to laboratory rodents by contaminated biological materials such as transplantable tumours, cell lines, sera or other biological materials. Biological materials are currently being screened using the mouse or rat antibody production (MAP/RAP) test (serological testing). We decided to test and validate an alternative assay using polymerase chain reaction (PCR/realtime PCR) technology to detect viral contamination directly in biological material.

Confirmed persistent mouse hepatitis virus infection and transmission by mice with a targeted null mutation of tumor necrosis factor to sentinel mice, using short-term exposure.

Mouse hepatitis virus (MHV) infection in immunocompetent mice is typically self limiting, and transmission is short lived. With the recent surge in the development of genetically engineered mutant mice with alterations in immune system components, however, MHV clearance may be disrupted. We report confirmed persistent transmission of MHV from tumor necrosis factor (TNF) knockout mice, B6.

Rodent quality assurance testing: use of sentinel animal systems.

The ability to produce unique strains of genetically engineered mice has revolutionized biomedical research, but has also complicated the maintenance of "clean" facilities through an increase in the movement of animals between facilities and the production of immunodeficient strains. The authors discuss the use of sentinel and quarantine programs to minimize disease transmission between laboratory mice.

Hypotensive infarction of the spinal cord in a rhesus macaque (Macaca mulatta).

A 6.5-year-old male rhesus macaque (Macaca mulatta) was presented with acute paraplegia following a surgical procedure. During surgery, he experienced an acute hypotensive episode that required 3 hours of supportive therapy before hemodynamic stability was restored.

The generation of monoclonal antibodies in mice: influence of adjuvants on the immune response, fusion efficiency and distress.

The objective of this study was to find a reliable alternative to Freund's adjuvant in order to reduce the distress imposed on the animals without impairing the fusion efficiency for immune-positive clones. For this purpose several commercially available adjuvants and adjuvant formulations representing different classes of molecules were compared. Humoral responses and animals' distress evaluated by clinical assessment and histopathological examinations were investigated and compared to fusion efficiencies.

Pathogenesis of guinea pig adenovirus infection.

Background And Purpose: The existence of guinea pig adenovirus (GPAdV) has been suspected on the basis of histopathologic findings, but the virus has not yet been isolated. In susceptible animals, it may cause severe bronchopneumonia and death. Adenovirus-like inclusion bodies have been observed in the lungs of animals with clinical disease.

Preparation and in vivo testing of porous alumina ceramics for cell carrier applications.

Microporous alumina was used to develop implantable cell carriers shaped as a hollow-sphere with a central opening to allow ingrowth of vascularised tissues. The carriers were produced by suspending the ceramic raw materials in water, homogenising and dropping the resulting slurry onto a heated plate (hot plate moulding, HPM). Morphological characteristics of the cell carriers were investigated by SEM and optical microscopy.

MHC-genotype of progeny influenced by parental infection.

In a previous series of in vitro fertilization experiments with mice we found non-random combination of major histocompatibility complex (MHC) haplotypes in the very early embryos. Our results suggested that two selection mechanisms were operating: (i) the eggs selected specific sperm; and (ii) the second meiotic division in the eggs was influenced by the type of sperm that entered the egg. Furthermore, the proportion of MHC-heterozygous embryos varied over time, suggesting that non-random fertilization was dependent on an external factor that changed over time.

Prevalence of enterotropic and polytropic mouse hepatitis virus in enzootically infected mouse colonies.

Mouse hepatitis virus (MHV) causes the most prevalent viral infection in contemporary laboratory mouse colonies. According to their primary replication site, different strains of MHV segregate into two overlapping biotypes, enterotropic and polytropic. These two groups vary greatly in disease pattern, pathogenicity, immune response, and duration of infection.

Enterotropic mouse hepatitis virus.

Mouse hepatitis virus [MHV], the coronavirus of the mouse, is the most common viral pathogen in contemporary laboratory mouse colonies throughout the world. It is highly contagious with variable clinical manifestations. The majority of infections are subclinical, but can still significantly influence biological responses, thus interfering with research, mainly in the field of immunology.

Recombinant genomic RNA of coronavirus MHV-A59 after coreplication with a DI RNA containing the MHV-RI spike gene.

A strategy for targeted RNA recombination between the spike gene on the genomic RNA of MHV-A59 and a synthetic DI RNA containing the MHV-RI spike gene is described. The MHV-RI spike gene contains several nucleotide differences from the MHV-A59 spike gene that could be used as genetic markers, including a stretch of 156 additional nucleotides starting at nucleotide 1497. The MHV-RI S gene cDNA (from nucleotide 277-termination codon) was inserted in frame into pMIDI, a full-length cDNA clone of an MHV-A59 DI, yielding pDPRIS.

[-Entrance of PCR for studying murine coronaviruses-].

This paper describes a number of applications of the Polymerase Chain Reaction (PCR) in the study of enterotropic murine coronaviruses [mouse hepatitis virus (MHV)]. A diagnostic PCR was developed which detected all of 11 different MHV strains. This fast and reliable method was also able to differentiate MHV from other non-murine coronaviruses.

[Mouse hepatitis virus].

Mouse hepatitis virus (MHV), the coronavirus of the mouse (mus musculus), is one of the most important viral pathogens in contemporary laboratory mouse colonies. It is a highly mutable virus consisting of numerous antigenically distinct serotypes with different pathology. These can be divided according to their tissue tropism into respiratory and enterotropic strains.

Enzyme-linked immunosorbent assay for detection of antibody to lymphocytic choriomeningitis virus in mouse sera, with recombinant nucleoprotein as antigen.

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of antibody to lymphocytic choriomeningitis virus (LCMV) in mouse sera. This assay is based on recombinant LCMV nucleoprotein generated in a baculovirus system. Sera from experimentally and naturally infected as well as noninfected mice were tested, and the results were compared with those obtained from an established immunofluorescence assay (IFA) that uses infected cells as antigen.

Molecular characterization of the S proteins of two enterotropic murine coronavirus strains.

Enterotropic strains of murine coronaviruses (MHV-Y and MHV-RI) differ extensively in their pathogenesis from the prototypic respiratory strains of murine coronaviruses. In an effort to determine which viral proteins might be determinants of enterotropism, immunoblots of MHV-Y and MHV-RI virions using anti-S, -N and -M protein-specific antisera were performed. The uncleaved MHV-Y and MHV-RI S proteins migrated slightly faster than the MHV-A59 S protein.

Sequence analysis of the nucleoprotein genes of three enterotropic strains of murine coronavirus.

The nucleotide sequences of the nucleoprotein genes of three enterotropic strains of the murine coronavirus mouse hepatitis virus (MHV-Y, MHV-RI and DVIM) were determined and compared with previously reported sequences of three polytropic (respiratory) strains (MHV-A59, MHV-JHM and MHV-S). Greater than 92% homology was found among the six strains by pair-wise comparison at the nucleotide level. The genes encoded proteins of 451 to 455 residues and the deduced amino acid sequences were more than 91% homologous.

[Procedures for health monitoring in a breeding facility for specific pathogen free mice and rats].

Causes of variation in animal experiments include differences in the genotype of the animals as well as a number of environmental factors. Through standardisation of the physical, chemical and biological components of the environment the quality of the results of the experiments can be improved, which in turn leads to a reduction of the number of animals used. One of the means to achieve this goal is the use of specified pathogen free (SPF) animals.

Transmission of murine viruses and mycoplasma in laboratory mouse colonies with respect to housing conditions.

Pathogen-free sentinel mice were placed in 7 animal rooms with different housing conditions and were serologically screened for antibodies to mouse hepatitis virus (MHV), pneumonia virus of mice (PVM), Sendai virus, reovirus 3, Theiler's mouse encephalomyelitis virus (TMEV), ectromelia virus and Mycoplasma pulmonis by enzyme-linked immunosorbent assays, at intervals after introduction. The most commonly detected antibody was against MHV, which was found in mice from 4 rooms, followed by PVM antibody in mice from 3 rooms. Seroconversion to Sendai virus and TMEV was detected in mice from one room each.

Nucleotide sequence comparison of the membrane protein genes of three enterotropic strains of mouse hepatitis virus.

The nucleotide sequences of the membrane (M) protein genes and their deduced amino acid sequences of three enterotropic strains of the coronavirus mouse hepatitis virus (MHV) -Y, -RI and -DVIM were determined and compared with the previously reported sequences of two respiratory MHV strains -A59 and -JHM. The five MHV strains shared extensive nucleotide (95.2-99.