Boron detection from blood samples by ICP-AES and ICP-MS during boron neutron capture therapy.

OBJECTIVE: The concept of boron neutron capture therapy (BNCT) involves infusion of a (10)B containing tracer into the patient's bloodstream followed by local neutron irradiation(s). Accurate estimation of the blood boron level for the treatment field before irradiation is required. Boron concentration can be quantified by inductively coupled plasma atomic emission spectrometry (ICP-AES), mass spectrometry (ICP-MS), spectrofluorometric and direct current atomic emission spectrometry (DCP-AES) or by prompt gamma photon detection methods. MATERIAL AND METHODS: The blood boron concentrations were analysed and compared using ICP-AES and ICP-MS to ensure congruency of the results if the analysis had to be changed during the treatment, e.g. for technical reasons. The effect of wet-ashing on the results was studied in addition. RESULTS: The mean of all samples analysed with ICP-MS was 5.8 % lower than with ICP-AES coupled to wet-ashing (R (2) = 0.88). Without wet-ashing, the mean of all samples analysed with ICP-MS was 9.1 % higher than with ICP-AES (R (2) = 0.99). CONCLUSIONS: Boron concentration analysed from whole blood samples with ICP-AES correlated well with the values of ICP-MS with wet-ashing of the sample matrix, which is generally considered the reference method. When using these methods in parallel at certain intervals during the treatments, reliability of the blood boron concentration values remains satisfactory, taking into account the required accuracy of dose determination in the irradiation of cancer patients.

Repeated human papillomavirus DNA findings among female university students.

In a previous study, we found a high (33%) human papillomavirus (HPV) DNA prevalence among first year university students in the Helsinki metropolitan area. We have now performed HPV rescreening among first-round HPV-positive students using a liquid-based hybridization assay. A total of 212 students participated in rescreening, and 82 (38.7%) of 212 were found to be positive for HPV DNA. Low-risk (lr) HPV DNA was repeatedly found in 16.8% of the patients who had been lr positive in the first screening round. High-risk (hr) HPV DNA was repeatedly found in 33.3% of the patients. Although HPV typing in these samples has not been carried out yet, we conclude that repeatedly positive HPV DNA findings were strikingly common. hrHPV DNA was repeatedly found twice as often as lrHPV DNA. HPV DNA prevalence was higher among oral contraceptive users than among patients using other contraception.

Plutonium in the air in Kurchatov, Kazakhstan.

Weekly air samples of 25000 m(3) volume were taken with two air samplers over a period of one year in 2000-2001 in the town of Kurchatov in Kazakhstan. For another three-month period in 2001, the samplers were run in the city of Astana, about 500 km west of Kurchatov. (137)Cs, Pu and U concentrations were determined from the filters. Pu activities in Kurchatov varied in a 100-fold range; median (239,240)Pu activities were 100 nBq/m(3) and (238)Pu activities 34 nBq/m(3). The corresponding values for Astana were considerably lower: 29 and 9 nBq/m(3), respectively, and in half of the filters the (238)Pu activity was below the detection limit. Plutonium concentration correlated with the amount of dust retained on the filters only at the highest dust loads. Also no correlation between wind speed and the plutonium activity in the filters was observed. Thus, resuspension does not seem to be the mechanism responsible for the airborne plutonium. No clear seasonal variation of Pu air concentration was observed, though levels were somewhat elevated in February to April. There was no correlation between the plutonium and (137)Cs concentrations. In most of the filters the cesium concentration was below the detection limit, but in those filters where it could be detected the cesium concentration was practically constant at 3.9+/-1.6 microBq/m(3). Dose estimation for the inhalation of the airborne plutonium gave a low value of 0.018 microSv/a for the inhabitants in Kurchatov, which is about a thousand times lower than the dose caused by the naturally occurring (210)Po. Air parcel trajectory analysis indicated that the observed Pu activities in the air could not unambiguously be attributed to the most contaminated areas at the Semipalatinsk Test Site.

Characterisation of projectiles composed of depleted uranium.

Projectiles suspected to be composed of depleted uranium (DU) were found in Kosovo. Their properties were analysed using alpha and gamma ray spectrometry, mass spectrometry and electron microscopy. They were found to be composed of DU with small amounts of other elements such as Ti. 236U was detected in the penetrators, reflecting the use of reprocessed fuel. No transuranium elements were detected. The typical external dose rate meter is not the best option for mapping the location of penetrators from the ground. Monte Carlo calculations were performed in estimating possible skin doses. Penetrators in long-lasting contact with skin may cause a notable equivalent dose to skin.

Premature rupture of the membranes: effect of penicillin prophylaxis and long-term outcome of the children.

To assess the value of prophylaxis with penicillin in women with premature rupture of membranes (PROM) and the long-term outcome of children born after prolonged PROM, we studied 221 women with this condition. Penicillin (5 mu twice, 6 hours apart) was given intravenously to 50 women and placebo to 51 women, whereas 76 comparable patients were treated without penicillin or placebo. The time interval between PROM and delivery ranged from 14 hours to 56 days. Chorioamnionitis occurred more frequently (p less than 0.05) among patients with placebo (14%) than among those treated with penicillin (2%). One puerperal endometritis appeared in the placebo group compared with none in the penicillin group. One newborn (1.7%) born to a mother with placebo prophylaxis developed septicemia, compared with none in the penicillin group. The outcomes of pregnancies complicated with PROM treated without penicillin or placebo were comparable with those in the placebo group. In addition, we compared somatic and psychomotor development of 159 children born to mothers with prolonged PROM (more than 12 hours; mean, 5.6 days; range, 14 to 1344 hours) with those of 43 children born at similar gestational age within 5 hours after PROM. No pulmonary sequelae could be linked to the long time period between PROM and delivery, but infants born soon after PROM more often (p less than 0.05) had cerebral palsy (8 of 43, 18.6%) than did infants born after prolonged PROM (7 of 159; 4.4%). We conclude that, in cases with PROM, penicillin prophylaxis decreases maternal and neonatal infectious morbidity and that the long interval between PROM and delivery does not impair the long-term outcome for these children.

Atomic emission method for total boron in blood during neutron-capture therapy.

BACKGROUND: Boron neutron-capture therapy (BNCT) is a drug-targeted binary radiotherapy for cancer. The (10)B capture of thermal neutrons induces secondary radiation within cells during irradiation. The most widely used boron carrier is 4-dihydroxyborylphenylalanine (BPA). The duration and timing of the irradiation is adjusted by monitoring (10)B concentrations in whole blood. METHODS: We developed a new method for boron determination that uses inductively coupled plasma atomic emission spectrometry (ICP-AES) and protein removal with trichloroacetic acid before analysis. This method was compared with the established but tedious inductively coupled plasma mass spectrometry (ICP-MS), which uses wet ashing as sample pretreatment. Erythrocyte boron concentrations were determined indirectly on the basis of plasma and whole blood boron concentrations and the hematocrit. The hematocrit was determined indirectly by measuring calcium concentrations in plasma and whole blood. RESULTS: Within- and between-day CVs were <5%. The recoveries for boron in whole blood were 95.6-96.2%. A strong correlation was found between results of the ICP-AES and ICP-MS (r = 0.994). Marked differences in plasma and erythrocyte boron concentrations were observed during and after infusion of BPA fructose complex. CONCLUSIONS: The present method is feasible, accurate, and one of the fastest for boron determination during BNCT. Our results indicate that it is preferable to determine boron in plasma and in whole blood. Indirect erythrocyte-boron determination thus becomes possible and avoids the impact of preanalytical confounding factors, such as the influence of the hematocrit of the patient. Such an approach enables a more reliable estimation of the irradiation dose.

Massive invasion of fetal lymphocytes into the mother's blood at induced abortion.

The proband, a healthy primipara, selected for study after she had asserted that she had not previously been pregnant, gave birth to a healthy girl with the karyotype 46,XX. In the 21st week of gestation, leukoagglutinin-stimulated mitoses from the proband's blood were 99% 46,XX and 1% 46,XY, the Y chromosome being identified by its quinacrine fluorescence. In two samples taken later in pregnancy no XY mitoses were found in the cultures, but on all three occasions brightly fluorescent Y chromatin in a proportion of the uncultured lymphocyte nuclei showed teh presence of XY cells in the proband's blood. High titers of cytotoxic anti-HL-A 3 were detected in the maternal serum before and after delivery. Our tentative interpretation is that the XY cells in the proband's blood emanated from a previous fetus that was legally aborted by curettage on the 10th week of an uneventful pregnancy and which the patient admitted to only after repeated questioning.

Transplacental passage of foetal blood cells.

With the brightly fluorescent Y chromatin as a marker, the proportion of foetal lymphocytes in maternal blood was found to be 0.02-0.16% in 7 of 11 primigravidae bearing a boy, but not a single XY mitosis was found among 112,000 leucoagglutinin-stimulated mitoses from the same women. The proportion of foetal lymphocytes did not change appreciably during pregnancy (first appearance detected at 15 weeks' gestation), nor were there any unequivocal foetal erythrocytes in spite of ABO and Rh compatibility. These findings suggest that foetal lymphocytes pass actively into the mother's blood relatively early during pregnancy. The cells are protected from immunological elimination, and therefore may remain in the maternal blood for long periods. They are a valuable potential source of material for antenatal foetal diagnosis.