Comparison of four commercially available rapid enzyme immunoassays with cytotoxin assay for detection of Clostridium difficile toxin(s) from stool specimens.

Rapid (2.5- to 3.5-h) enzyme immunoassays (EIAs) for the detection of Clostridium difficile toxins have been developed. We report the results of simultaneous testing of 700 fresh stool specimens by the tissue culture cytotoxin assay and four EIAs (Bartels Prima System C. difficile Toxin A EIA, Cambridge Biotech Cytoclone A+B EIA, Meridian Diagnostics Premier C. difficile Toxin A EIA, and TechLab C. difficile Tox-A Test EIA). In cases of disagreement, culturing for toxigenic C. difficile was performed. A total of 61 (8.7%) specimens from 46 patients were positive for C. difficile toxin. The sensitivity of the cytotoxin assay was 87%, and that of culture was 93%. In comparison with the cytotoxin assay results, the sensitivity and specificity of the EIAs were as follows: Bartels, 87 and 96%; Cambridge, 89 and 99%; Meridian, 87 and 98%; and TechLab, 87 and 95%, respectively. In comparison with the cytotoxin assay plus toxigenic culture results, the sensitivity and specificity of the EIAs were as follows: Bartels, 84 and 97%; Cambridge, 85 and 99%; Meridian, 79 and 98%; and TechLab, 80 and 96%, respectively. The EIAs varied in positive predictive values (PPVs). A high PPV was seen with the Cambridge EIA (96%); lower PPVs were seen with the TechLab (64%), Bartels (72%), and Meridian (80%) EIAs because of high false-positive rates. The negative predictive values (98 to 99%) were excellent with all EIAs. Results were indeterminant with 0.3% of the samples by the Meridian EIA and 3% by all the other EIAs. Although the EIAs were less sensitive than the cytotoxin assay, they provide same-day results and may be useful in laboratories without tissue culture facilities.

Morbidity study of extruder personnel with potential exposure to brominated dioxins and furans. I. Results of blood monitoring and immunological tests.

The potential for exposure of employees to polybrominated dibenzofurans (PBDFs) and dibenzo-p-dioxins (PBDDs) during extrusion blending of resins containing decabromodiphenyl ether was established through previous air monitoring (area samples) and biomonitoring studies. The findings presented herein are further biomonitoring results for 42 employees and immunological tests for exposed and referent employees. Among potentially exposed men, 2,3,7,8-TBDF and 2,3,7,8-TBDD concentrations in blood lipid ranged from non-detectable to 112 parts per trillion (ppt) and from non-detectable to 478 ppt respectively. Biomonitoring results correlated well with assignments in the extruder work area when adjusted for process changes and engineering improvements and provided biological half life estimates of between 1.1 and 1.9 years for 2,3,7,8-TBDF and between 2.9 and 10.8 years for 2,3,7,8-TBDD. Results for 16 measures of the immune system were examined in relation to exposure (exposed v referent group) and in relation to the biomonitoring data. Some individual trends in immunological parameters with exposure and covariates such as age and cigarette smoking were found (for example, an increase in complement C4 with increasing concentrations of PBDFs and PBDDs, increased lymphocyte subpopulation counts with cigarette smoking); however, the overall clinical assessment was that the immune system of exposed employees was not adversely impacted at these burdens of PBDFs and PBDDs.

Vitamin A gastrointestinal absorption in persons with Down's syndrome.

The total daily vitamin A intake, physical signs associated with vitamin A deficiency, and the response to a vitamin A challenge were studied in 33 patients with Down's syndrome and in 14 intellectually normal persons (comparison group). The evaluation of detailed dietary histories revealed that the study subjects' mean daily vitamin A intake was similar to the recommended daily allowance for adults and that there was no significant difference of the mean daily vitamin A intake between study and comparison groups (5029 IU and 5706 IU, respectively). Subjects with Down's syndrome had more symptoms usually seen in patients with hypovitaminosis A than the persons in the comparison group. The baseline serum vitamin A levels in the Down's syndrome and comparison groups were within the normal range (106.0 micrograms/dl and 136.5 micrograms/dl, respectively). The vitamin A absorption curve of persons with Down's syndrome paralleled that of normal individuals and no significant difference of vitamin A levels between study and comparison groups was observed except for the 6-h values. Also, the absorption differential (delta = 3-h value + 6-h value/2-O-h value) did not show a significant difference between the two groups. Thus, these investigations do not support previous reports of significantly decreased vitamin A absorption in individuals with Down's syndrome.

Symptomatic atlantoaxial subluxation in persons with Down syndrome.

In a prospective study 40 of 236 individuals with Down syndrome were found to have atlantoaxial instability. Whereas most of the 40 affected children were asymptomatic, seven patients exhibited various neuropathology. Historical data, neurologic findings, radiologic interpretations, and surgical management of these seven patients are described in detail. In addition, case reports of other individuals with Down syndrome and symptomatic atlantoaxial subluxation from the literature were analyzed. We conclude that early identification of these patients and appropriate surgical management, including reduction of the subluxation and posterior cervical spine fusion, will in most instances result in a favorable outcome; however, patients with long-standing symptoms and marked neuronal damage show no or only little improvement postoperatively.

Risk-taking and the adolescent hemophiliac.

To evaluate the clinical impression that hemophiliacs express a high level of interest in physical activities associated with a significant risk of major bleeding, a self-administered questionnaire was given to the 17 hemophilic adolescents 11-19 years of age in a state hemophilia program, and to 17 age-matched non-hemophilic adolescents. Scores for risk-taking attitudes, anticipated risk-taking behavior were calculated for 23 activities. Compared with controls, hemophiliacs neither express greater risk-taking attitudes, anticipate greater risk-taking behavior, nor appear more likely to carry out the behavior. Hemophiliacs 15-19 years of age appear more likely to carry out the stated risk-taking behaviors when compared with younger (ll-14-year-old) hemophiliacs but not when compared with matched older.non-hemophiliacs. Risk-taking activities selected by hemophiliacs tend to be adaptive for the limitations imposed by their illness. The conclusion that hemophiliacs appear more likely to engage in risk-taking behavior as they get older, although the express no greater overall interest in risk-taking than do non-hemophilic adolescents, needs to be confirmed by behavioral observations as home care programs improve the activity potential of young hemophiliacs.