Isolation and characterization of adenovirus 5 from the brain of an infant with fatal cerebral edema.

This report describes a fatal case of cerebral edema caused by adenovirus in a previously healthy 18-month-old infant who developed skin rash, pulmonary congestion, and fever and who died 6 days later. Adenovirus hexon gene sequences were detected in brain tissue and brain tissue cultures. The virus was typed as adenovirus 5.

A practical and accurate method for the determination of 234Th simultaneously with 210Po and 210Pb in seawater.

A practical technique has been developed for the determinations of (234)Th simultaneously with (210)Po and (210)Pb in seawater samples, which greatly simplifies the on-board chemical procedures and enables an accurate correction of (234)Th ingrowth. A unique feature of this technique lies in the exact determination of co-precipitated (238)U following Fe(OH)(3) precipitation which leads to an exact correction of ingrown (234)Th between Fe(OH)(3) precipitation and U/Th separation. Such a correction eliminates several cumbersome on-board chemistry steps (such as Po plating, Fe(2+) oxidation, and 9 N HCl anion exchange) required in regular procedures to eliminate the (234)Th ingrowth. The total time required for on-board sample treatment (spike equilibration, Fe (OH)(3) co-precipitation and filtration) could be less than 10 h which significantly increases the sample processing efficiency and data throughput.

Lead isotopes in the western North Atlantic: transient tracers of pollutant lead inputs.

In the early 1980s, Patterson and colleagues demonstrated that most lead in oceanic surface waters had an anthropogenic origin. Their discovery occurred during the phasing out of leaded gasoline in North America initiated in the previous decade. The corresponding decrease in the anthropogenic lead emissions, verified by Pb/210Pb ratios, accounted for the systematic decline in lead concentrations in surface waters of the western Sargasso Sea. Subsequent changes in anthropogenic lead inputs to the western Sargasso Sea surface waters have been documented by measurements of lead concentrations, isotopic compositions (206Pb/207Pb, 208Pb/206Pb), and Pb/210Pb ratios in precipitation and seawater for the period of 1981 to 1994. These data indicate the easterly trade winds are now the primary source of atmospheric lead in Bermuda, and they confirm that the decline of lead concentrations in the North Atlantic is associated with the phasing out of leaded gasoline in North America and western Europe over the past decade. Moreover, temporal variations in the relative contribution of industrial lead inputs from the two sides of the North Atlantic over that period can be quantified based on differences in their isotopic composition. The transient character of those isotopic signatures also allows calculations of pollutant lead penetration rates into the mixed layer and upper thermocline of the western Sargasso Sea.

An efficient quantitative technique for the simultaneous analyses of radon daughters (210)Pb, (210)Bi and (210)Po.

An improved and time efficient technique has been developed for quantitative determination of the long-lived (222)Rn daughters ((210)Pb, (210)Po and (210)Bi) in atmospheric and oceanic samples. The sample is first spiked with yield tracers for polonium (208 or 209), bismuth (207), and lead (stable lead carrier). These nuclides may then be scavenged through iron hydroxide precipitation and redissolved in a dilute (pH approximately 2) nitric acid plating medium with citrate and hydroxylamine hydrochloride at 90 degrees centrigrade with constant stirring. First a silver planchet is suspended in the solution which plates polonium to high efficiency. Second, a nickel planchet is suspended in the same solution which is maintained hermetic (e.g. bubbling with helium) and bismuth is plated next with high efficiency. Third, lead is purified from the same solution using anion exchange techniques and isolated for beta counting as the sulfate. Polonium is analyzed by isotope dilution alpha spectrometry. Bismuth and lead are analyzed by anti-coincident beta counting in a low level shield. In the case of bismuth, the 207 tracer is added in quantities at least comparable to the background of the beta system such that counting before and after the decay of (210)Bi gives the bismuth yield. The unique characteristics of this technique are its speed and efficiency; all three radon daughters can be isolated for counting within 4 hr of pre-treating the sample. The remaining solution can be treated subsequently for other analyses as appropriate.

Inorganic and organic sulfur cycling in salt-marsh pore waters.

Sulfur species in pore waters of the Great Marsh, Delaware, were analyzed seasonally by polarographic methods. The species determined (and their concentrations in micromoles per liter) included inorganic sulfides (

The estuarine surface microlayer and trace metal cycling in a salt marsh.

The aqueous surface microlayer in a Delaware salt marsh carries an average of 10 percent of the copper, 19 percent of the zinc, and 23 percent of the iron relative to the total metal flux including the dissolved and seston components. Such trace metals cycle in the salt marsh by net import on the surface microlayer and net export in the dissolved and seston components during maximum monthly tides.