ABSTRACT
BACKGROUND: Human bocavirus (HBoV) is a newly identified human parvovirus for which seroepidemiology and antigenic properties remain undefined. METHODS: The HBoV VP2 gene, expressed from a baculovirus vector, produced virus-like particles (VLPs), which were used to raise rabbit anti-HBoV antisera and to develop an enzyme-linked immunosorbent assay (ELISA). The VLP-based ELISA was used to screen for HBoV-specific immunoglobulin G antibodies in a convenience sample of 270 serum specimens, mostly from children, obtained at Yale-New Haven Hospital; 208 specimens were also screened for erythrovirus B19-specific antibodies by a B19 VLP-based ELISA. RESULTS: Immunofluorescence and ELISA showed that human parvoviruses HBoV and B19 are antigenically distinct. By the HBoV VLP-based ELISA, 91.8% and 63.6% of serum specimens from infants in the first and second months of life, respectively, were found to be seropositive, as were 45.4% from 3-month-old infants and 25.0% from 4-month-old infants. The percentages of HBoV-seropositive children increased to 40.7%-60.0% for children 5-47 months of age and to >85% for individuals >or=48 months old. However, the overall percentage of B19-seropositive individuals was <40.5% for all age groups screened. CONCLUSIONS: HBoV infection is common during childhood, but a minority of children and young adults screened have evidence of B19 infection.
Subject(s)
Bocavirus/isolation & purification , Capsid Proteins/genetics , Parvoviridae Infections/epidemiology , Adolescent , Adult , Amino Acid Sequence , Animals , Antibodies, Viral/blood , Antigens, Viral/immunology , Bocavirus/genetics , Bocavirus/immunology , Capsid Proteins/chemistry , Capsid Proteins/metabolism , Cell Line , Child , Child, Preschool , Humans , Immunoprecipitation , Infant , Molecular Sequence Data , Parvoviridae Infections/diagnosis , Parvoviridae Infections/immunology , Parvovirus B19, Human/immunology , Parvovirus B19, Human/isolation & purification , Rabbits , Recombinant Proteins , Seroepidemiologic Studies , Virion/genetics , Virion/immunology , Virion/isolation & purificationABSTRACT
Alkaline phosphatase and acid phosphatase are two major enzymatic measures of osteoblastic and osteoclastic activity, respectively. As a result, the preservation of the enzymes in bone specimens to near in vivo accuracy is essential. Despite standardization of the staining process, several factors related to the storage of blocks and slides before sectioning and staining impact the level of enzymes detected in the tissue. Block condition (intact, faced, or unstained) as well as environment (temperature and length of time in storage) affect alkaline phosphatase preservation while the acid phosphatase enzyme remains unaffected. We conclude that to optimally preserve alkaline phosphatase enzyme, methacrylate-embedded undecalcified murine bones should be stored as intact blocks. After sectioning, the faced blocks should be stored at 4°C for optimal enzyme staining of future sections. Furthermore, it is best to stain sections immediately after sectioning.
