title: Nitrate, nitrite and volatile N-nitroso compounds in the urine of Schistosoma haematobium and Schistosoma mansoni infected patients.
abstract: The present study presents, for the first time, the amounts of nitrate, nitrite and volatile N-nitroso compounds in saliva and urine samples of Schistosoma haematobium and Schistosoma mansoni infected patients. Mid-morning saliva and 24 h urine samples were collected from male patients infected with S.haematobium (n = 129 saliva and 79 urine samples) and S.mansoni (n = 64 saliva and 65 urine samples) and in a comparative control group of healthy individuals (n = 27) from the Nile Delta region of Egypt. Saliva samples were analyzed for the presence of nitrate and nitrite; while urine samples were analyzed for the presence of nitrate, nitrite and volatile N-nitroso compounds. In the control group, N-nitroso-dimethylamine (NDMA) was detected at concentrations (mean +/- SD) of 0.27 +/- 0.47 microgram/day. N-Nitrosopiperidine (NPIP; 0.6 microgram/day) and N-nitrosopyrrolidine (NPYR; 0.4 microgram/day) were also present in one sample. S.mansoni infected subjects showed significantly (P < 0.001) higher levels of 2.9 +/- 2.9 micrograms/day NDMA and a higher frequency of NPIP (in 40/65 samples; 0.4 +/- 0.3 microgram/day) and NPYR occurrence (in 59/65 samples; 0.9 +/- 0.9 microgram/day). Significant further increases in the excretion of volatile N-nitroso compounds were found in S.haematobium-infected patients with mean daily excretion of 19.2 +/- 21 micrograms/day NDMA (in all samples; P < 0.001), 1.6 +/- 2.3 micrograms/day NPIP (in 56/79 samples; P < 0.001) and 1.3 +/- 1.9 micrograms/day NPYR (in 58/79 samples; P < 0.1). The differences either in salivary nitrite/nitrate or in urinary nitrite between the three distinct groups were not significant. However, the urinary excretion of nitrate was elevated from 139 +/- 82 mg/day in the control group to 249 +/- 126 mg/day in S.mansoni infected patients (P < 0.001) and to 174 +/- 176 mg/day in S.haematobium infected subjects (P < 0.005 in comparison to S.mansoni infected group). These results suggest a possible role of N-nitroso compounds in the etiology of schistosome-associated bladder cancer and imply a partial participation of S.mansoni in the multistage process of urinary schistosomiasis-associated bladder carcinogenesis.
authors.affiliation: Department of Environmental Studies, Alexandria University, Egypt.
authors.forename: M H
authors.initials: MH
authors.lastname: Mostafa
authors.forename: S
authors.initials: S
authors.lastname: Helmi
authors.forename: A F
authors.initials: AF
authors.lastname: Badawi
authors.forename: A R
authors.initials: AR
authors.lastname: Tricker
authors.forename: B
authors.initials: B
authors.lastname: Spiegelhalder
authors.forename: R
authors.initials: R
authors.lastname: Preussmann
mesh_terms: D000328:Adult; D004534:Egypt; D006801:Humans; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000652:urine*; D009573:Nitrites / Q000652:urine*; D009603:Nitroso Compounds / Q000652:urine*; D012463:Saliva / Q000378:metabolism; D012553:Schistosomiasis haematobia / Q000652:urine*; D012555:Schistosomiasis mansoni / Q000652:urine*
chemical_list: D009566:Nitrates; D009573:Nitrites; D009603:Nitroso Compounds