The Maternal Lifestyle Study: drug use by meconium toxicology and maternal self-report.

OBJECTIVE: The objective of this study was to describe drug use by pregnant women participating in the 4-site Maternal Lifestyle Study of in utero cocaine and/or opiate exposure. METHODS: Meconium specimens of 8527 newborns were analyzed by immunoassay with GC/MS confirmation for metabolites of cocaine, opiates, cannabinoids, amphetamines, and phencyclidine. Maternal self-report of drug use was determined by hospital interview. RESULTS: The prevalence of cocaine/opiate exposure in the 4 sites was 10.7% with the majority (9.5%) exposed to cocaine based on the combination of meconium analysis and maternal self-report. However, exposure status varied by site and was higher in low birth weight infants (18.6% for very low birth weight and 21.1% for low birth weight). Gas chromatography/mass spectrometry (GC/MS) confirmation of presumptive positive cocaine screens was 75.5%. In the cocaine/opiate-exposed group, 38% were cases in which the mother denied use but the meconium was positive. There was 66% agreement between positive meconium results and positive maternal report. Only 2% of mothers reported that they used only cocaine during pregnancy and mothers were 49 times more likely to use another drug if they used cocaine. CONCLUSION: Accurate identification of prenatal drug exposure is improved with GC/MS confirmation and when the meconium assay is coupled with a maternal hospital interview. However, the use of GC/MS may have different implications for research than for public policy. We caution against the use of quantitative analysis of drugs in meconium to estimate the degree of exposure. Our study also highlights the polydrug nature of what used to be thought of as a cocaine problem.

Antibody response in humans to influenza virus type B host-cell-derived variants after vaccination with standard (egg-derived) vaccine or natural infection.

Hemagglutination inhibition (HI) and neutralization tests were used to determine antibody responses to egg-derived and Madin-Darby canine kidney (MDCK)-derived influenza B virus (B/England/222/82) in paired sera from persons naturally infected with influenza B and in persons vaccinated with standard egg-derived inactivated influenza vaccine. When tested by HI, the MDCK-derived antigen gave significantly higher (8- to 12-fold) geometric mean titers (GMT) in convalescent-phase sera from persons naturally infected during community outbreaks, as well as more 4-fold titer rises, than did tests with egg-derived antigen. When tested by neutralization, however, the convalescent-phase sera GMTs were only threefold higher with the MDCK-derived antigen and an equivalent number of fourfold titer rises were detected with both antigens. With postvaccine sera, the MDCK-derived antigen gave GMTs that were threefold higher than those obtained with egg-derived antigen in both the HI and neutralization tests and both antigens detected an equivalent number of fourfold titer rises in HI and neutralization tests. Sucrose gradient-fractionated egg-derived antigen showed a single peak of hemagglutinin activity corresponding to whole virions, whereas MDCK-derived antigen contained two distinct peaks of hemagglutinin activity, one of which had a lower sedimentation rate. The overall findings indicate that the egg-derived antigen in the vaccine induced HI and neutralizing antibody to both egg- and MDCK-derived variants and suggest that titers of antibody to MDCK-derived virus may be affected by the physical form of the hemagglutinin antigen.

Time-resolved fluoroimmunoassay with monoclonal antibodies for rapid diagnosis of influenza infections.

Monoclonal antibodies that are broadly reactive with either influenza A or influenza B viruses were used to develop a 2- to 3-h antigen capture time-resolved fluoroimmunoassay (TR FIA) for detecting influenza viral antigens in both original nasopharyngeal aspirate specimens and in tissue cultures inoculated with nose or throat swab specimens. The lower limit of sensitivity of the assay was about 10 pg of protein as determined with purified influenza A nucleoprotein expressed by recombinant DNA. When the TR FIA was performed with 96 nasopharyngeal aspirate specimens collected during outbreaks of influenza A (H3N2) virus and the results were compared with serodiagnosis results with paired sera, the specificity and sensitivity of TR FIA for the demonstration of influenza A infections were 95 and 85%, respectively. In culture confirmation assays, more than 80% of the swab specimens that grew influenza A or B virus within 7 days could be identified by the TR FIA within 48 h of the inoculation of cells. The results are consistent with those previously reported for respiratory syncytial virus and extend the applicability of monoclonal antibody-based TR FIA for the rapid diagnosis of acute respiratory viral infections.

Characterization and evaluation of monoclonal antibodies developed for typing influenza A and influenza B viruses.

Monoclonal antibodies that are broadly reactive with influenza A or influenza B viruses were produced as stable reagents for typing influenza viruses. Monoclonal antibodies to influenza A were specific for either matrix protein or nucleoprotein. The antibodies to influenza B were specific for nucleoprotein or hemagglutinin protein. In an enzyme immunoassay procedure, influenza A antibodies detected H1N1, H2N2, and H3N2 influenza A virus strains collected between 1934 and 1984. Each of the influenza B antibodies detected influenza B reference viruses collected between 1940 and 1984. Pools of either influenza A or influenza B monoclonal antibodies were used to detect influenza viruses reisolated from clinical specimens in tissue culture. At 48 h after inoculation, the influenza A monoclonal antibodies detected 64% of H1N1 and 94% of H3N2 influenza A specimens, and the influenza B monoclonal antibodies detected 79% of the influenza B specimens. The results of this study suggest that the monoclonal antibodies described should provide useful diagnostic reagents for workers in virology laboratories who wish to isolate and identify influenza virus but have been unable to obtain consistent supplies of animal sera specific for influenza A or B viruses.

Experimental allergic neuritis-like disease in rabbits after injection with influenza vaccines mixed with gangliosides and adjuvants.

An experimental allergic neuritis-like disease was induced in rabbits 3 to 8 weeks after injection with large doses of influenza vaccines mixed with gangliosides, cholesterol, and Freund complete adjuvant. The inclusion of gangliosides was essential to induce the experimental allergic neuritis-like disease. In trials with six different lots of vaccine, both swine influenza and non-swine influenza vaccines produced by four different manufacturers induced experimental allergic neuritis-like disease in 26 of 43 inoculated rabbits.

Characterization of antibodies to orthopoxviruses in human sera by radioimmunoassay.

Serological surveillance of suspected orthopoxvirus infections in man is important for confirming the success of the worldwide smallpox eradication programme. An adsorption radioimmunoassay (RIA) was used to differentiate sera from patients who were naturally infected with human monkeypox or variola virus, and individuals who were immunized with vaccinia virus. The antisera were adsorbed with uninfected chicken chorioallantoic membrane (CAM) and vaccinia-infected CAM before reacting in RIA with vaccinia, monkeypox, and variola antigens. Each serum group showed characteristic patterns of residual antibody activity which made it possible to identify antibody specificities.When 45 human sera were tested by this method, 71% were identified as having vaccinia, variola, or monkeypox adsorption characteristics, while the remaining 29% could not be identified. Of the identified sera, 9 were characteristic of vaccinia, 8 of variola, and 15 of monkeypox. Six of the 15 monkeypox sera were virologically confirmed monkeypox infections, 6 were suspected monkeypox infections but were not virologically confirmed, and 3 were of unknown aetiology.The adsorption RIA provides a method of identifying serologically the poxvirus responsible for infection long after the acute phase of illness.

A study of the specificities of sequential antisera to variola and monkeypox viruses by radioimmunoassay.

The specificities of antisera during development of the humoral antibody response to poxvirus antigens were examined in monkeys injected with chimp-9 whitepox virus or monkeypox virus. Sera were obtained from 3 African green (vervet) monkeys inoculated with chimp-9 whitepox virus, 1 rhesus monkey inoculated with monkeypox virus, and 2 rhesus monkeys inoculated with soluble monkeypox viral antigen. The sequentially obtained sera from each animal were adsorbed with uninfected chicken chorioallantoic membranes (CAM) or vaccinia virus-infected CAM. The adsorbed sera were tested by radioimmunoassay to determine the specificity of the residual antibodies to vaccinia, variola, and monkeypox viruses. The adsorbed sera at different stages of the immune response showed increasing specificity with time after inoculation. Generally, antibodies in sera collected earlier than 21-27 days after immunization could not be identified after adsorption, but late sera could be identified unequivocally.