Daily boron intake from the American diet.

Interest in boron as a naturally occurring trace element nutrient from the food supply is increasing. Mounting evidence suggests that boron is essential to human beings. This study explores the major food and beverage contributors of boron and estimates of daily boron intake from the American diet. Previous estimates in the literature of dietary boron consumption are based on limited foods and population segments. In this study we provide a more comprehensive assessment of boron consumption by the US population. A boron nutrient database of 1,944 individual foods was developed. These foods represent 95.3% by weight of all foods consumed in the US Department of Agriculture 1989-1991 Continuing Survey of Food Intakes by Individuals (1989-1991 CSFII). The Boron Nutrient Database (version 1.0) was then linked to the 3-day food records of 11,009 respondents to the 1989-1991 CSFII to generate the average daily boron intake for each person. The weighted 5th percentile, median, mean, and 95th percentile boron intakes, respectively, are 0.43, 1.02, 1.17 and 2.42 mg/day for men; 0.33, 0.83, 0.96 and 1.94 mg/day for women; and 0.40, 0.86, 1.01 and 2.18 mg/day for pregnant women. For vegetarian adults, these intakes are 0.46, 1.30, 1.47 and 2.74 mg/day for men and 0.33, 1.00, 1.29 and 4.18 mg/day for women. The top 2 boron contributors, coffee and milk, are low in boron, yet they make up 12% of the total boron intake by virtue of the volume consumed. Among the top 50 boron contributors, peanut butter, wine, raisins, peanuts, and other nuts are high in boron. As more data become available on daily boron requirements, the results of this study may be used to assess whether Americans' daily intake of boron is adequate.

Sources of human exposure: overview of water supplies as sources of boron.

Boron (B) is widely distributed in surface and groundwaters predominantly as undissociated boric acid, and is found in ocean waters at a mean level of approx 4.6 mg B/L. A recent analysis of US surface waters indicated that the 10th, 50th, and 90th percentile B levels were 0.010, 0.076, and 0.387 mg B/L, respectively. The same study found that the 50th and 90th percentile B levels in California drinking waters were 0.10 and 0.40 mg B/L, respectively. The overall mean B concentration in Canadian surface waters in 1988 was reported to be 0.16 mg B/L, with a few stations reporting concentrations above 2.0 mg B/L. Unusually high levels of B have been measured in human water supplies of northern Chile, with concentrations ranging from 0.31 to 15.2 mg B/L. River water sources of B in the UK and Northern Italy were found to range from 0.002 to 0.87 mg B/L, respectively, whereas German drinking waters had median and maximum B levels of 0.02 and 0.18 mg B/L, respectively. Bottled mineral water also represents a source of B exposure based on the largest reported survey of US and European products, with a mean level of 0.75 mg B/L and a range from <0.005 to 4.35 mg B/L. Thus, B intake from drinking water is highly variable and dependent on the geographic source, the quantities of water consumed and the water sources used to bottle other beverages.

Growth of a leiomyosarcoma of the inferior vena cava.

Until recently, leiomyosarcoma of the inferior vena cava was rarely diagnosed preoperatively. The authors describe a patient who was treated for 12 months on the basis of a presumptive diagnosis of thrombosis of the inferior vena cava. Abdominal ultrasonography and computed tomography demonstrated interval growth, and venous biopsy revealed a malignant spindle-cell neoplasm. Surgical excision confirmed the presence of a leiomyosarcoma, which had grown slowly for at least several months before entering a phase of accelerated growth.

Detection of acute cholecystitis in children.

Hepatobiliary imaging has an established diagnostic role in adults with acute cholecystitis but is underutilized in children. The authors report two children with acute cholecystitis, whose condition was diagnosed with the aid of a 99m-technetium-labeled iminodiacetic acid (IDA) derivative. The diagnosis was confirmed surgically.

Metrizamide myelography in conjoined lumbosacral nerve roots.

Conjoined lumbosacral nerve roots are a congenital anomaly found at 1% of lumbar disc operations. They are usually present at the L5-S1 level and may or may not be associated with herniated intervertebral discs. Previously it had been thought that the preoperative myelogram was not helpful in diagnosis but using metrizamide myelography the diagnosis should be made more often by observing: (a) an asymmetric subarachnoid space, (b) a common axillary pouch exiting between opposite upper and lower nerve root sheaths, (c) a widened axillary pouch, and (d) two or more individual nerve roots in the axillary pouch.

Gas-liquid chromatography and mass spectrometric ion selective detection of sterigmatocystin in grains.

A method was developed for direct gas-liquid chromatographic-mass spectrometric (GLC-MS) analysis of nonderivatized sterigmatocystin in wheat, rice, barley, and corn. Sterigmatocystin was extracted from spiked grain samples by 2 methods, both of which yielded high recoveries of 14C-labeled sterigmatocystin (greater than 90%). Extracts were cleaned up by gel permeation chromatography on polystyrene with tetrahydrofuran as the eluant. Chromatography of 14C-labeled compound indicated good recoveries (greater than 90%). The GLC-MS system was modified to give an all-glass chromatographic pathway to the ion source. Short glass or quartz columns packed with silicone liquid phase on inert supports gave the best results. Trace levels of sterigmatocystin were very labile in all gas chromatographic systems and levels below 5 ppb in grains were detected only with great difficulty. The GLC-MS system was utilized in the mass fragmentography mode, with selective ion monitoring of the m/e 295, 306, and 324 peaks. These ions were present in only trace levels in all control grain samples, indicating minimal interference from other compounds. The limit of accurate detectability (20 ng) on spiked grain samples was lower than previously reported. Lower levels of sterigmatocystin (1 ppb or 4 ng on column) could be detected in grains by using the mass fragmentography mode, but these levels could not be measured accurately.