RESUMO
BACKGROUND: Porcine clotting factor has been used for more than 15 years to treat severe bleeding episodes in persons with hemophilia who have antibodies to human clotting factor. In 1996, QC procedures revealed for the first time the presence of porcine parvovirus (PPV) in the product. This report describes an investigation to determine the extent of product contamination and to evaluate past recipients of porcine clotting factor (Hyate:C, Speywood Biopharm) for evidence of PPV infection. STUDY DESIGN AND METHODS: Stored specimens from 22 lots of previously released Hyate:C were tested for the presence of PPV DNA by PCR and nested PCR assays. Serum specimens from 98 recipients of Hyate:C and 24 controls who did not receive Hyate:C were tested for PPV antibodies by an immunofluorescence assay. RESULTS: PPV DNA was detected in product from 21 of the 22 lots of Hyate:C, primarily by nested PCR testing. In contrast, none of the serum specimens from the 98 Hyate:C recipients tested positive for PPV IgG antibodies. CONCLUSION: The risk of human disease from percutaneous exposure to low levels of PPV seems to be low. Nevertheless, the theoretical risk of human infection with PPV has led to manufacturing changes, including PCR screening of all porcine plasma, which are designed to eliminate this risk.
Assuntos
Anticorpos Antivirais/sangue , DNA Viral/sangue , Contaminação de Medicamentos , Fator VIII/efeitos adversos , Hemofilia A/complicações , Infecções por Parvoviridae/veterinária , Parvoviridae/isolamento & purificação , Doenças dos Suínos/transmissão , Suínos/virologia , Adulto , Animais , Canadá/epidemiologia , Hemofilia A/terapia , Humanos , Masculino , Parvoviridae/genética , Parvoviridae/imunologia , Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/transmissão , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Estudos Soroepidemiológicos , Método Simples-Cego , Suínos/sangue , Estados Unidos/epidemiologia , Viremia/veterinária , ZoonosesRESUMO
A technique is described for the quantitative determination of the distributed growth of Saccharomyces cerevisiae immobilized in polyacrylamide gel. Gel specimens were embedded in paraffin or gelatin and paraffin before sectioning and staining. Photomicrographs of specimen sections were enlarged, and cell microcolony volumes were determined as a function of position in the gel by grid transparency analysis. Overall cell densities within the gel were calculated for a quantitative comparison with values measured by a second spectrophotometric method. The results show good agreement and demonstrate the sigmoidal growth of the immobilized cells, reaching a maximum steady-state value. The technique shows promise as a general method for following the transient growth of organisms immobilized within gel particles.