Extended forensic evaluation when sexual abuse is suspected: a multisite field study.

A subset of children referred due to suspected sexual abuse require more than one interview for professionals to reach an opinion about the veracity of allegations. The National Children's Advocacy Center's forensic evaluation model was designed for that specific group of children. The multisite study of the model reported here followed a 2-year pilot study. Professionals in 12 states adopted the model and collected data for 2 years on a total of 147 participants. In 44.5% of the cases, a credible disclosure was obtained, with 73% of these cases supported in the legal system. The forensic evaluation procedure yielded clear information to be used in child protection and prosecutory decisions in 64% of the cases (combining cases with credible disclosures and abuse unlikely findings). Finally, the study examined the effects of the length of the evaluation and of the case and child characteristics on evaluation outcomes.

Automated contrast fluorometry. I. Lymphocytotoxicity testing.

Automated contrast fluorometry has been carried out in lymphocytotoxicity testing using a computer-controlled microscope and direct comparison of the data with controls. The method uses heparinized lymphocytes and permits simultaneous evaluation of both fluorescein and ethidium bromide fluorescence by calculating the quotient between the green/red measurements. After comparison of the quotient with that of control samples, the raw data are automatically transformed into cytotoxicity scores. Fast and reliable measurements with minimum background fluorescence can be obtained for up to 24 hours after performance of the assay by controlling complement reactivity and the exposure time of the cells to the fluorescein. The evaluation of 15,204 cytotoxic reactions showed excellent correlation between the automated and visual results of 125 tissue typings using 120 different antibodies and of 17 HLA antibody titers using case-by-case analysis of variance. The values for the automated cytotoxicity readings were slightly higher and showed more intermediate scores than those of the visual readings suggesting a high sensitivity and objectivity of the automated system. In conclusion, this is a methods paper comparing parallel lymphocytotoxicity testing using automated and manual methods. The automated method was found to be more sensitive and faster than the manual method.

Is serum the optimal source for HLA antibodies?

The cytotoxic reactivity of 18 predefined class I HLA serum antibodies was compared with that of antibody preparations containing anticoagulants. ACD-A, EDTA, 4% citrate and heparin plasmas all showed lower cytotoxicity than serum antibodies. Recalcification of both platelet-rich and platelet-poor ACD-A plasma did not fully restore the antibody reactivity, suggesting a detrimental effect of calcium chelation. This effect was exclusive of volume or of any platelet or plasma protein involvement. The changes in pH contributed to the lower reactivity and to the increased lympholytic effect, whereas adjusting the pH toward the serum value improved the reactivity. Heat-inactivated antibodies showed only a slightly reduced cytotoxicity. Heparin had the least effect of all anticoagulants on the reactivity, although in heparin there was a definite dose-dependent decline in cytotoxic titer which was probably related to anticomplementary activity. Calcium chelators, such as EDTA and citrate, showed marked cytotoxic inhibition at half the usual complement concentration. This effect was more pronounced when the anticoagulant and lymphocytes were incubated prior to cytotoxicity testing. At the complement concentrations used, the inhibitory effects of the citrate anticoagulants appeared to be primarily calcium-related. Inhibition tests, serial titrations and testing of varying calcium concentrations confirmed the superiority of serum as antibody source.

Nonspecific suppressor cells in rheumatoid arthritis. Con A and PHA induced suppressor cell activity.

Suppression of the blastogenic response by autologous cells precultured with Concanavalin A (Con A) or Phytohemagglutinin (PHA) was studied in an in vitro system. The mean mitogen response of cells from normal individuals and from patients with Rheumatoid Arthritis (RA) in isologous plasma was similar. In isologous plasma there was no significant difference between the activity of Con A suppressor cells of normals and those of RA. Incubation of the cells in RA plasma abrogated the suppression in both normals and RA patients. In isologous plasma PHA suppressor cells were also induced in both groups, the levels being lower in the normals than in the RA group. PHA suppressor cell activity against PWM induced blastogenesis could not be engendered in normals. RA plasma abrogated PHA suppressor cell activity, especially in the RA group. The abrogating activity of RA plasma was heat stable, nondialysable and could be correlated with the presence of anti-lymphocyte antibodies in the RA plasma.