Development and evaluation of a microtiter plate enzyme immunoassay for antibodies to 3,3'-dichlorobenzidine

The authors obtained and evaluated antisera from rabbits injected with a derivative of a potent bladder carcinogen, dichlorobenzidine (DCB), conjugated to bovine serum albumin (BSA). A 14C-radioimmunoassay (RIA) was able to detect the presence of DCB antibodies, but its relative insensitivity led to the development of a more sensitive enzyme immunoassay (EIA). The EIA test was a "sandwich" method in which a second antibody, labeled with an enzyme (horseradish peroxidase), was used to measure antibody binding to transferrin (Tf)-conjugated DCB immobilized on a microtiter plate. Antibody titers measured by RIA were approximately 1:40; when measured by EIA, they were approximately 1:40,000. Antibody specificity was assessed by comparing the antibody binding activities of DCB, BSA, Tf, BSA-conjugated to DCB, and a number of N-substituted aromatic compounds that included benzidine (Bz). Among the compounds tested, the rabbit antiserum reacted only with DCB and the carrier protein, BSA. Moreover, antibody binding activity to Tf-conjugated DCB was significantly inhibited by unconjugated DCB concentrations between 30 and 500 ng/mL. The precision of antibody binding activities as a function of DCB concentration (expressed by the CV) ranged from 9% for low (30 ng/mL) DCB levels to 12% for higher (500 ng/mL) levels. This evaluation suggests that the antiserum obtained would be appropriate for detecting DCB levels at the ng/mL level.     

Natural history of endemic type D retrovirus infection and acquired immune deficiency syndrome in group-housed rhesus monkeys

A 2.5-year epidemiologic study of a breeding group of rhesus monkeys (Macaca mulatta), which is a focus of endemic simian acquired immunodeficiency syndrome (SAIDS), demonstrated a strong association between the occurrence of SAIDS and infection with a type D retrovirus, SAIDS retrovirus serotype 1 (SRV-1). Of 23 healthy "tracer" juvenile rhesus monkeys, 19 (83%) died with SAIDS within 9 months of introduction into the resident SAIDS-endemic population. In contrast, 21 healthy "sentinel" juvenile rhesus monkeys placed in the same outdoor enclosure but denied physical contact with the SAIDS-affected group by a 10-foot-wide "buffer zone" remained free of SRV-1, SRV-1 antibody, and disease for 2.5 years. The SAIDS-specific mortality rate was significantly higher in juveniles than in adults. In repeated serologic testing, the overall prevalence of SRV-1 antibody ranged from 68 to 85%. Antibody prevalence increased with age. Seroconversion was found to be a poor indicator of infection rate, as approximately 50% of virus-positive juvenile monkeys had no antibody detectable by enzyme-linked immunosorbent assay. Repeated viral isolations from all animals revealed 1) SRV-1 viremia with clinical SAIDS; 2) persistent viremia and viral shedding in apparently healthy animals; 3) transient viremia and clinical recovery; 4) intermittent viremia, suggesting activation of latent infections; and 5) viremia in a 1-day-old infant, suggesting transplacental transmission. The prevalence of SRV-1 antibody in SAIDS-free breeding groups of rhesus monkeys was 4%. The seroprevalence of antibodies against human T-cell leukemia virus type 1 (HTLV-1), human immunodeficiency virus (HIV), and simian immunodeficiency virus (SIV; formerly STLV-III) was uniformly low or absent in both SAIDS-free and SAIDS-affected groups of rhesus monkeys, demonstrating that these retroviruses are not etiologically linked to SAIDS at the California Primate Research Center.     

Aggressive resection of metastatic disease in selected patients with malignant gastrinoma.

Fifteen patients with Zollinger-Ellison syndrome followed at the National Institutes of Health with extensive metastatic disease had an actuarial 5-year survival of 20%. Therefore, in 1982 a prospective study to examine the effect and feasibility of removing all gross tumor in selected patients with extensive metastatic disease was instituted. Five patients with extensive metastatic gastrinoma confined to the abdomen in whom imaging studies suggested the possibility of complete surgical resection were entered into this study and underwent attempted complete surgical resection and chemotherapy with streptozotocin, doxorubicin, and 5-fluorouracil. Median follow-up was 24 months. Surgical resection of all gastrinoma was possible in 4/5 patients attempted. In one patient in whom all gross disease could not be resected, the residual tumor progressed and the patient died 19 months after operation. All four patients with all disease resected appeared to benefit since all of them had a significant reduction in antisecretory medications and are enjoying normal activity and work. Three patients have had no detectable tumor on follow-up, and two of these patients are clinically and biochemically "cured" with normal fasting gastrin levels and negative provocative gastrin tests at 14 and 32 months. Therefore, aggressive resection of metastatic disease in selected patients with malignant gastrinoma is recommended.     

Predictors of Hand Function Following Digit Replantation: Quantitative Review and Meta-Analysis

Background: Digit replantation affords the opportunity to restore hand function following amputation. To date, however, few studies have evaluated functional outcomes following replantation. Therefore, it was the objective of this study to perform a meta-analysis to better characterize the predictors of hand function. Methods: A literature search was performed using the PubMed database to identify studies that focused on digit amputation/replantation and functional outcomes. Studies were evaluated for patient- and injury-related factors and their respective effects on clinical outcomes of sensation, grip strength, and Disabilities of the Arm, Shoulder, and Hand (DASH) scores. Statistical analysis was conducted across the pooled data set to identify significant trends. Results: Twenty-eight studies representing 618 replanted digits were included in this study. We found the average grip strength was 78.7% (relative to contralateral), the average 2-point discrimination (2PD) was 7.8 mm, and the average DASH score was 12.81. After conducting statistical analysis, we found patients with more proximal injuries had lower grip strength scores (P < .05). We found 2PD scores were influenced by age, mechanism of injury, and amputation level (P < .05). Finally, we found DASH scores after replantation were predicted by mechanism of injury and level of amputation (P < .05). The following variables did not influence outcomes: gender, tobacco use, ischemia time, and digit number. Conclusions: Digit replant does not restore premorbid hand function but does result in adequate hand function. Expected functional outcomes following replant should be considered in the decision-making process. These data can help risk-stratify patients, guide postreplant expectations, and influence the decision for replantation.     

Nucleotide sequence,serology and symptomatology suggest that vanilla necrosis potyvirus is a strain of watermelon mosaic virus II

Summary Vanilla necrosis potyvirus (VNV) is the cause of significant losses to the South Pacific islands vanilla crop. The gene for the coat protein of VNV has been cloned and sequenced. Comparison of this gene with other potyviral coat protein sequences revealed 97% nucleotide sequence homology (98% amino acid homology) to a US isolate of watermelon mosaic virus II (WMV-II), 93% nucleotide sequence homology (96% amino acid homology) to an Australian isolate of WMV-II and 81% nucleotide sequence homology (88% amino acid homology) to soybean mosaic virus-N (SMV-N). Serological analysis, by Western blot and ELISA, confirmed the close relationship between VNV and WMV-II. Furthermore, a limited host range determination found VNV and WMV-II able to infect the same series of test plants. However, symptoms differed significantly on three test species demonstrating that VNV and WMV-II are not identical in biological properties. We suggest that VNV be renamed WMV-II (Tonga).