Environmental fate and effects of dicamba: a Canadian perspective.

Literature on the environmental fate and effects of the benzoic acid herbicide dicamba was reviewed to provide a scientific basis to derive Canadian Water Quality Guidelines. Included in the review was information on the uses and production of dicamba, its physical and chemical properties, environmental monitoring data in Canadian surface water and groundwater, soils, sediments, and biota, and its environmental degradation, persistence, and fate. Through monitoring, dicamba has been detected in less than 8% of surface-water samples to a maximum concentration of 13 micrograms.L-1, while 2% of groundwater samples were positive up to 517 micrograms.L-1. Only one study that analyzed sediments (with no detections) and no field studies that investigated residues in biota were found. Microbial degradation is the most important process governing the dissipation of dicamba in aquatic and soil environments. Photolysis, hydrolysis, volatilization, adsorption to sediment, and bioconcentration are not expected to be significant removal processes, based on limited environmental fate data. The half-life of dicamba in water is < 7 d, although residues have been detected in surface-water supplies in Alberta more than 6 mon after application. The literature reports the half-life in soils ranges from 4 to 555 d; however, < 12 wk would be typical under Canadian conditions. High moisture and temperature, and other conditions that favor microbial degradation, would likely reduce the half-life to < 4 wk. The principal soil and plant metabolite is 3,6-dichlorosalicylic acid, with minor amounts of 2,5-dihydroxy-3,6-dichlorobenzoic acid and 5-hydroxydicamba found. Dicamba is highly mobile in soil, and significant leaching is possible; its water solubility is 6.5 g.L-1 (25 degrees C) and it has a log octanol-water partition coefficient of 0.477. Acute and chronic toxicological studies for all nontarget plants and animals were also reviewed. The major groups of organisms for which toxicological data were collected were freshwater fish, invertebrates and plants, tame hays and cereals, legumes, and other crops, and livestock poultry and mammals. The acute toxicity (< or = 96-hr LC50) to freshwater fish ranged from 28 to 516 mg.L-1, whereas that for invertebrates ranged from 3.9 to > 100 mg.L-1. No chronic data were found for either of these groups. The chronic EC50 to 14 freshwater algae, based on growth inhibition, ranged from 100 to > 10,000 micrograms.L-1. No studies on freshwater macrophytes or any marine organisms were found. Agricultural crops exhibited varying toxicity.(ABSTRACT TRUNCATED AT 400 WORDS)

Epstein-Barr virus (EBV). IV. Studies on experimental inactivated vaccine against human EBV infection.

It is well established that EBV-immunogen successfully invoke a strong neutralizing anti-EBV response in experimental animals. The authors report here the successful production of an EBV-immunogen prepared with whole disrupted productive cells of 2 MEBV cell line and with whole virus inactivated with ethylenimine (EI) which produce neutralizing anti-EBV response in experimental animals (calves, sheep, rabbits and SPF chickens).

Epstein-Barr virus (EBV). V. Incidence of EBV antibodies in patients with rheumatic diseases.

Serum samples from 95 patients with rheumatoid arthritis, 24 patients with other various rheumatic diseases, 50 patients with diabetes mellitus, 34 patients with acute viral infections, 6 patients with infectious mononucleosis, 77 patients with lymphomas and leukemia and 110 blood donors and 24 healthy subjects as normal controls, respectively, were tested by indirect immunofluorescence (IF) reaction for the presence of specific antibodies against Epstein-Barr virus determined viral capsid antigen (anti-VCA) and Epstein-Barr active viral infection. The IF test carried out in acetone-fixed smears of EB-3 cell line revealed EB antibodies anti-VCA in 83.3% of infectious mononucleosis, 61.0% lymphomas and leukemia, 58.0% diabetic patients. The frequency of anti-VCA antibodies in rheumatic patients was 31.4%, and 3.6% and 25% in sera from blood donors and healthy subjects, respectively. Incidence of active EBV infection was 5.7% of rheumatic diseases, 17.7% of acute virus infections, 50.0% of infectious mononucleosis, and 31.1% of lymphomas and leukemia patients. Active EBV infection was not found out in blood donors (0/110) and healthy subjects (0/24) groups as control. Rheumatoid arthritis with or without rheumatoid factor patients had serological evidence of active EBV infection 6/26 and 4/26 respectively.

Epstein-Barr virus (EBV). VI. Incidence of EBV antibodies in patients with malignant lymphoproliferative diseases.

Serum samples from 52 patients with malignant lymphoproliferative diseases and 12 clinically healthy subjects were tested by indirect immunofluorescence (IF) reaction for the presence of specific EB antibodies anti-VCA and active EBV infection. The tests revealed EB antibodies anti-VCA in 32 patients with lymphoproliferative diseases and in 2 clinically healthy subjects and active EBV infection in 18/32 and in 0/2 EB anti-VCA positive patients and clinically healthy subjects, respectively.

Epstein-Barr virus (EBV). X. Incidence of EBV antibodies in patients with malignant tumors.

Serum samples from 31 patients with various types of malignancies, 18 patients with different viral infections and 6 healthy subjects as controls, were tested by indirect immunofluorescence (IF) method for antibodies against viral capsid antigens (VCA) and the presence of active EBV infection. EBV antibodies anti-VCA were detected in 19 patients with tumors, in 8 patients with viral infections and in 2 healthy subjects. EBV active infection was found out in 9/19, 3/8 and 0/2 EBV anti-VCA positive patients with malignancies, different viral infections and healthy subjects respectively.

Epstein-Barr virus (EBV). III. Incidence of EBV antibodies in patients with various tumors.

Serum samples from 553 patients with various tumors, from 26 patients with different viral infections and from 78 clinically healthy subjects were tested by indirect immunofluorescence (IF) reaction for the presence of specific antibodies to Epstein-Barr virus. The test revealed antibodies to EBV in 127 patients with tumors, in 14 patients with viral infections and in 8 healthy persons.

Epstein-Barr virus (EBV). VII. Established lymphoid cell line (IVPat-88) obtained from synovial fluid of a patient with aseptic arthritis.

Attempts have been made to culture mononuclear cells from synovial fluid of 8 patients with arthropathy, and have led to the development of the lymphoid cell line IVPat-88. Cell line has been propagated by serial passages for more than 14 weeks in continuous culture. The cells grew as single, free-floating individuals, or in dense clumps without adherence to glass or plastic surface. All these cells were identified as altered lymphoblasts because of their growth pattern and uniform morphology, and the presence of Epstein-Barr Viral Capsid Antigen (VCA) in 5 to 10% of the cells. The cell concentration varied during the period of culture from about 300,000 to 1,700,000 cells per ml, and mean doubling time during phases of active growth was 42 and 60 hours in MEM and RPMI 1640 tissue culture media, respectively. The methods used and the characteristics of the cell line are described.