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.

Vitamin B-6 status during childhood: tracking from 2 months to 11 years of age.

To examine the development and tracking of long-term vitamin B-6 status from infancy to early adolescence, measurements of erythrocyte pyridoxal 5'-phosphate concentration (EPLP), the erythrocyte aspartate transaminase (EAST) stimulation test including measurements of basal activity (EASTo) and activation coefficient (alpha EAST), were made in a follow-up study of healthy children aged 2 (n = 139), 4 (n = 147), 6 (n = 157), 9 (n = 159) and 12 mo (n = 188) and 5 y (n = 148). The EAST stimulation test was repeated at 11 y (n = 153). Vitamin B-6 status, high during infancy, reached the adult level by 5 y of age. The 10th to 90th percentile ranges for EPLP values were 61-201 nmol/L at 4 mo, 49-101 nmol/L at 12 mo and 27-59 nmol/L at 5 y. The respective ranges for Easto were 16-24 microkat/L at 4 mo, 13-19 microkat/L at 12 mo, 9-14 microkat/L at 5 y and 25-39 microkat/L at 11 y of age. For alpha EAST values were 1.29-1.54 at 4 mo, 1.48-1.77 at 12 mo, 1.70-2.07 at 5 y and 2.00-2.57 at 11 y. Values for EPLP and the EAST stimulation test in the first year of life correlated with the values at 5 and 11 y. The individuals with values at the extreme ends of the distributions remained there from infancy to childhood up to 3.3 times more often than expected from random variation.(ABSTRACT TRUNCATED AT 250 WORDS)

Lack of association between indices of vitamin B1, B2, and B6 status and exercise-induced blood lactate in young adults.

By means of a 5-week vitamin B-complex supplementation, associations between indices of vitamin B1, B2, and B6 status (activation coefficients [AC] for erythrocyte transketolase, glutathione reductase, and aspartate aminotransferase) and exercise-induced blood lactate concentration were studied. Subjects, 42 physically active college students (18-32 yrs), were randomized into vitamin (n = 22) and placebo (n = 20) groups. Before the supplementation there were no differences in ACs or basal enzyme activities between the groups. The ACs were relatively high, suggesting marginal vitamin status. In the vitamin group, all three ACs were lower (p < 0.0001) after supplementation: transketolase decreased from 1.16 (1.14-1.18) (mean and 95% confidence interval) to 1.08 (1.06-1.10); glutathione reductase decreased from 1.33 (1.28-1.39) to 1.14 (1.11-1.17); and aspartate aminotransferase decreased from 2.04 (1.94-2.14) to 1.73 (1.67-1.80). No changes were found after placebo. Despite improved indices of vitamin status, supplementation did not affect exercise-induced blood lactate concentration. Hence no association was found between ACs and blood lactate. It seems that marginally high ACs do not necessarily predict altered lactate metabolism.

Gradual and rapid weight loss: effects on nutrition and performance in male athletes.

We studied seven male wrestlers and three judo athletes (weight 55-93 kg) during two weight reductions. In the "gradual" procedure (GP), a 5.0 +/- 0.4% (mean +/- SEM) weight loss was achieved in 3 weeks by energy restriction. In the "rapid" procedure (RP), 6.0 +/- 0.6% of body weight was lost in 2.4 days by fluid and diet restriction and forced sweating, and followed by a 5-h "loading" (food and drinks ad libitum). The net weight loss after GP and loading was 2.7 +/- 0.5%. Protein intakes (4-d food records) during GP and RP were 71 +/- 16 and RP 56 +/- 17 g.d-1, respectively. Carbohydrate intakes were 239 +/- 56 (GP) and 182 +/- 55 g.d-1 (RP). During GP and RP, mean thiamin, magnesium, and zinc intakes were at or below the respective recommendation. Thiamin, riboflavin, potassium, iron, and zinc status, assessed from blood chemistry, remained stable during both procedures. Changes in vitamin B6 indicator (E-ASTAC) and S-magnesium concentration were different (P < 0.01) between the procedures, suggesting negative trends during GP. Sprint (30-m run) and anaerobic (1-min Wingate test) performance was similar throughout the study. Following GP, vertical jump height with extra load increased by 6-8% (P < 0.01). Jumping results were not affected by RP. Hence, < or = 5% loss in body weight by either method did not impair experienced athletes' performance.

A study with a follow-up of the effects of music education on holistic development of empathy.

Half of the 32 children, aged 6 yr. old, took part in the 12-hr. holistic empathy education program with music exercises over three months. Others were controls. Children were tested at a pretest, 3 months later at the posttet after the training, and follow-up test, 9 months after posttest. The Feshbach and Roe Empathy Slide Test, the Weir and Duveen Prosociability Rating Scale, and the Kalliopuska Prosociability Rating Scale for Teachers were used. Empathy and prosociability increased significantly from pretest to posttest after empathy education. As hypothesized, comparison of pretest and follow-up test results showed a significant increase in empathy for the test group and a nonsignificant increase among controls.

Dietary intake and thiamin, iron, and zinc status in elite Nordic skiers during different training periods.

This study evaluated how different training periods affect dietary intake and biochemical indices of thiamin, iron, and zinc status in elite Nordic skiers. Subjects were 17 skiers and 39 controls, ages 18-38 yrs. Dietary data were collected by 7-day food records at 3-month intervals. Coefficient of variation (CV) was used to indicate magnitude of seasonal changes. Energy intake for the year (28 food record days) was 3,802 kcal/day (CV 19.1%) in male skiers, 2,754 kcal/day (CV 3.7%) in male controls, 2,812 kcal/day (CV 9.1%) in female skiers, and 2,013 kcal/day (CV 5.9%) in female controls. CVs for thiamin, riboflavin, vitamin C, calcium, magnesium, iron, and zinc intake were 14.1-23.9% (male skiers), 2.9-15.0% (male controls), 4.8-24.5% (female skiers), and 4.3-11.5% (female controls). Seasonal changes in energy, carbohydrate, and micronutrient intakes reflected energy expenditure in male endurance athletes particularly. Erythrocyte transketolase activation coefficients and serum ferritin and zinc concentrations did not differ between skiers and controls. Seasonal variations in these biochemical indices of nutritional status were of the same magnitude in skiers and controls, despite large changes in skiers' physical activity.