Serodiagnosis of human brucellosis by an indirect ELISA test using recombinant outer membrane protein 19 kDa (rOMP19) as an antigen.

BACKGROUND: Brucellosis remains one of the global health concerns that reemerges in recent years. Delayed or inaccurate diagnosis end to a long treatment duration and financial burden; therefore, finding a good antigen for detection of specific anti-Brucella antibodies is crucial. We intended to evaluate the serodiagnosis value of recombinant Brucella outer membrane protein 19 kDa (rOMP19) using indirect ELISA system compared with Rose Bengal test. RESULTS: The OMP19 sequence was successfully cloned into pET-28a and produced in E. coli cells (DE3). After extraction and purification of rOMP19, this protein was used for designing indirect ELISA to detect anti-Brucella antibodies in 73 human sera, including 6 brucellosis-positive and 67 brucellosis-negative samples. The accuracy of rOMP19 ELISA was evaluated by receiver operating characteristic (ROC) curve and then compared with Rose Bengal plate test and a commercial anti-IgG Brucella ELISA kit. In comparison with Rose Bengal plate test, the area under the ROC curve was 0.985 (95% CI, 0.96-1.00). From coordinates of the curve, the optimal cut-off value was selected at 0.147, in which the diagnostic sensitivity was 100%, and the specificity was 94%. At this cut-off point, 10 samples were diagnosed as positive (6 true positives and 4 false positives), while negative samples were all correctly diagnosed. The results of our designed rOMP19 ELISA was the same as data obtained from commercial ELISA kit, which applied LPS as an antigen. CONCLUSIONS: We concluded that OMP19 is an efficient antigen for the serodiagnosis of human brucellosis.

Latex agglutination test based on single-chain Fv recombinant antibody fragment.

Recombinant antibodies have been proposed as invaluable tools for various therapeutic and diagnostic purposes. Here, we describe the development of a novel latex agglutination test (LAT) using single-chain Fv recombinant antibody fragment for the detection of K99(+) enterotoxigenic Escherichia coli strains. For the production of a single-chain Fv antibody fragment (scFv) against the major colonization factor (FanC) of K99 antigen, the scFv gene was integrated into a bacterial expression vector under the control of T7 promoter. After high-level expression of soluble scFv (approximately 50 mg/l) in flask cultivation of E. coli DE3 and purification, scFv was immobilized on different latex particles, and then, these sensitized beads were used in LAT. Results obtained with our latex reagents revealed that the recombinant antibody-coated particles were able to give a good agglutination signal with purified antigen, intact cells displaying this protein and clinical specimens. The strength of agglutination of scFv-coated beads for antigen was comparable to that of polyclonal anti-K99-coated particles. However, the assay proved to be simple and rapid, similar to conventional LATs, and owing to more convenient and economical production of recombinant antibodies, they can be considered as a useful reagent for replacing monoclonal antibodies in LATs.

A comparison of nurse and patient perceptions of chemotherapy treatment stressors.

To assess how closely nurses and patients considered various situations as causing stress in chemotherapy treatment, this study was designed to compare nurse and patient perceptions of chemotherapy treatment stressors for patients in an oncology hospital. This descriptive study was conducted in the summer of 1997. Fifty patients receiving cytotoxic treatment were chosen by random sample. All 21 registered nurses of the Tabriz University of Medical Sciences who worked in the oncology department were contacted. A Likert-type questionnaire was designed to measure the stressfulness of commonly occurring items in chemotherapy treatment. The intensity of each item was measured by a scale with response choices ranging from the most to the least important. The patients were asked to indicate their perceptions of the seriousness of stress by sorting items. The nurses were asked to complete the same questionnaire as the patients completed. The greatest physical stressor mentioned by the patients was fatigue (66%), and by nurses, alopecia (62%). The nurses' perceptions of psychosocial items causing the greatest stress included fear of disease recurrence (90.5%), fear of death (90.5%), economic problems (90.5%), and appearance changes (90.5%), whereas the patients perceived dependency (80%), economic problems (70%), and loss of social activity (66%), as the greatest stressors (p < 0.05). The findings showed disagreement between the two groups on intensity of physical and psychosocial stressors (p < 0.05). The results from this study increased nurses' awareness of important stress factors in chemotherapy treatment. Identification of the situations perceived to be more stressful than others helped clinical nurses to modify their care and provide for their patients in a way that removes or reduces the stressors.

Antimutagenic effects of vitamin E on oncology and non oncology hospital nurses by comet assay.

Vitamin E is a natural antioxidant and its most common biologically active form is α-tocopherol. The antiproliferative effects of α-tocopherol have been previously demonstrated. In this study the antimutagenic effects of vitamin E on oncology and non oncology hospital nurses was investigated. A total of 138 female nurses from oncology and non oncology hospitals participated in the study. They received 200 mg/day vitamin E for 2 weeks. The urine samples before and after intake of vitamin E were collected and the nucleus of urothelial cells were evaluated with comet assay. The length of epithelial cells nuclei correlated with increased fracture rate of DNA. Nucleolus length of urine epithelial cells of all nursing staff before and after vitamin E treatment were measured and the data were evaluated by student t-test and SPSS. Our study showed that 20% of nursing staff have apoptosis and DNA fracture in the nucleolus of their urine epithelial cells and DNA damage in the urothelial cells of exposed nurses was significantly higher than the control group (P<0.05).The antimutagenic activity of vitamin E had significant effects on oncology hospital nurses effectively in repairing DNA damage and decreasing their nucleus length in urine epithelial cells.We propose that the higher therapeutic doses of vitamin E and increasing the length of treatment period will be effective against DNA strand breakage and may have more effect on oncology nurses.