Insights Into Elevated Distortion Product Otoacoustic Emissions In Sickle Cell Disease: Comparisons of Hydroxyurea-treated and Non-treated Young Children

Distortion product otoacoustic emissions (DPOAEs) were examined in 15 normal- hearing African-American children between the ages of 6 and 14 years with homozygous sickle cell disease (SCD), who were on a regimen of hydroxyurea (HDU), a drug that reduces inflammatory processes and symptoms of SCD; a matched group of 15 African- American children with homozygous SCD not on HDU; and 15 African-American children with normal hemoglobin. DPOAEs were evoked by 13 primary tone pairs with f2 frequencies ranging from 1000 to 4500 Hz. Increased DPOAE amplitudes, believed to be a precursor of eventual hearing loss, were evident in children with SCD who were not receiving HDU. Those taking HDU had DPOAE amplitudes similar to normal controls. These findings suggest that HDU, in addition to reducing symptoms of SCD, may play a role in inhibiting or preventing cochlear pathology and hearing loss in individuals with SCD. Key Words: distortion product otoacoustic emissions; sickle cell disease; hydroxyurea Abbreviations: ABR = auditory brainstem response; DPOAE = distortion product otoacoustic emission; HDU = hydroxyurea; HbSS = homozygous sickle cell disease; ICAM = intercellular adhesion molecule; M = mean; OAE = otoacoustic emission; p = probability; PECAM = platelet-endothelial cell adhesion molecule SCD = sickle cell disease; SD = standard deviation of the mean; SOAE = spontaneous otoacoustic emission; TEOAE = transient evoked otoacoustic emission; VCAM = vascular cell adhesion molecule

(Figures 6-9, page 98-100) Annotated record of the detailed examination of Mn deposits from the Waho Shelf, Hawaii Islands

Detailed mapping of manganese deposits in the Kauai Channel and on the Waho Shelf adjacent to the northwest corner of Oahu is near completion. Manganese crusts and nodules are concentrated on submarine terraces between 800 and 2400 meters deep. Similarities In the geomorphology and sedimentary conditions where extensive manganese deposits are present suggest that these are primary factors controlling manganese distribution in the Hawaiian Archipelago. This information may be useful for guiding future surveys, and the technology developed for studiesiIn the Hawaiian Archipelago may have application to other areas of high topographic relief and low sediment thickness (i.e., seamounts, fracture zones, fault scarps, ridges, etc.)

Annotated record of the detailed examination of Mn deposits from R/V Robert Conrad Cruise 8 stations

The cores and dredges described in this report were taken during the Robert Conrad Cruise 8 from November 1963 until August 1964 by the Lamont Geological Observatory, Columbia University from the R/V Robert Conrad. A total of 140 cores and dredges were recovered and are available at Lamont-Doherty Earth Observatory for sampling and study

Annotated record of the detailed examination of Mn deposits from VEMA 10 Expedition stations

The cores and dredges described in this report were taken during the VEMA 10 Expedition from June until September 1956 by the Lamont Geological Observatory, Columbia University from the R/V Vema. A total of 95 cores were recovered and are available at Lamont-Doherty Earth Observatory for sampling and study