M.P. Salganik

Early Intervention in Low Birth Weight Premature Infants: Results at 18 Years of Age for the Infant Health and Development Program

OBJECTIVE. To assess whether improvements in cognitive and behavioral development seen in preschool educational programs persist, we compared those in a multisite randomized trial of such a program over the first 3 years of life (INT) to those with follow-up only (FUO) at 18 months of age. METHODS. This was a prospective follow-up of the Infant Health and Development Program at 8 sites heterogeneous for sociodemographic characteristics. Originally 985 children were randomized to the INT (n = 377) or FUO (n = 608) groups within 2 birth weight strata: heavier low birth weight (HLBW; 2001–2499 g) and lighter low birth weight (LLBW; ≤2000 g). Primary outcome measures were the Peabody Picture Vocabulary Test (PPVT-III), reading and mathematics subscales of the Woodcock-Johnson Tests of Achievement, youth self-report on the Total Behavior Problem Index, and high-risk behaviors on the Youth Risk Behavior Surveillance System (YRBSS). Secondary outcomes included Weschler full-scale IQ, caregiver report on the Total Behavior Problem Index, and caregiver and youth self-reported physical health using the Medical Outcome Study measure. Assessors were masked as to study status. RESULTS. We assessed 636 youths at 18 years (64.6% of the 985, 72% of whom had not died or refused at prior assessments). After adjusting for cohort attrition, differences favoring the INT group were seen on the Woodcock-Johnson Tests of Achievement in math (5.1 points), YRBSS (−0.7 points), and the PPVT-III (3.8 points) in the HLBW youth. In the LLBW youth, the Woodcock-Johnson Tests of Achievement in reading was higher in the FUO than INT group (4.2). CONCLUSIONS. The findings in the HLBW INT group provide support for preschool education to make long-term changes in a diverse group of children who are at developmental risk. The lack of observable benefit in the LLBW group raises questions about the biological and educational factors that foster or inhibit sustained effects of early educational intervention.

The Effect of Chelation Therapy with Succimer on Neuropsychological Development in Children Exposed to Lead

BACKGROUND Thousands of children, especially poor children living in deteriorated urban housing, are exposed to enough lead to produce cognitive impairment. It is not known whether treatment to reduce blood lead levels prevents or reduces such impairment. METHODS We enrolled 780 children with blood lead levels of 20 to 44 microg per deciliter (1.0 to 2.1 micromol per liter) in a randomized, placebo-controlled, double-blind trial of up to three 26-day courses of treatment with succimer, a lead chelator that is administered orally. The children lived in deteriorating inner-city housing and were 12 to 33 months of age at enrollment; 77 percent were black, and 5 percent were Hispanic. Follow-up included tests of cognitive, motor, behavioral, and neuropsychological function over a period of 36 months. RESULTS During the first six months of the trial, the mean blood lead level in the children given succimer was 4.5 microg per deciliter (0.2 micromol per liter) lower than the mean level in the children given placebo (95 percent confidence interval, 3.7 to 5.3 microg per deciliter [0.2 to 0.3 micromol per liter]). At 36 months of follow-up, the mean IQ score of children given succimer was 1 point lower than that of children given placebo, and the behavior of children given succimer was slightly worse as rated by a parent. However, the children given succimer scored slightly better on the Developmental Neuropsychological Assessment, a battery of tests designed to measure neuropsychological deficits thought to interfere with learning. All these differences were small, and none were statistically significant. CONCLUSIONS Treatment with succimer lowered blood lead levels but did not improve scores on tests of cognition, behavior, or neuropsychological function in children with blood lead levels below 45 microg per deciliter. Since succimer is as effective as any lead chelator currently available, chelation therapy is not indicated for children with these blood lead levels.

Centroid-moment tensor solutions for July–September 1991

Centroid-moment tensor solutions are presented for 142 earthquakes that occurred during the third quarter of 1991. The solutions are obtained using corrections for aspherical structure represented by a whole mantle shear velocity model, SH8/U4L8, of Dziewonski and Woodward.

Centroid-moment tensor solutions for January–March 1994

Abstract Centroid-moment tensor solutions are presented for 143 earthquakes that occurred during the first quarter of 1994. The solutions are obtained using corrections for aspherical earth structure represented by a whole mantle shear velocity model SH8/U4L8 of Dziewonski and Woodward (1992, in: Acoustical Imaging, Plenum Press, 19; 785–797). A new model of anelastic attenuation of Durek and Ekstrom (1994, EOS, Trans. Am. Geophys. Un., Spring Meeting Suppl., 75: 83) is used to predict the decay of the waveforms.

CENTROID-MOMENT TENSOR SOLUTIONS FOR OCTOBER-DECEMBER 1995

Abstract Centroid-moment tensor solutions are presented for 219 earthquakes that occurred during the fourth quarter of 1995. The solutions are obtained using corrections for aspherical earth structure represented by a whole mantle shear velocity model SH8/U4L8 of Dziewonski and Woodward (1992). A new model of anelastic attenuation of Durek and Ekstrom (1996) is used to predict the decay of the waveforms.

Centroid-moment tensor solutions for October–December 1994

Abstract Centroid-moment tensor solutions are presented for 231 earthquakes that occurred during the fourth quarter of 1994. The solutions are obtained using corrections for aspherical earth structure represented by a whole mantle shear velocity model SH8/U4L8 of Dziewonski and Woodward (Acoustical Imaging, 1992, Vol. A, pp. 785–797). A new model of anelastic attenuation of Durek and Ekstrom (EOS, 1994, 75:83) is used to predict the decay of the waveforms.

CENTROID-MOMENT TENSOR SOLUTIONS FOR JULY-SEPTEMBER 1995

Abstract Centroid-moment tensor solutions are presented for 230 earthquakes that occurred during the third quarter of 1995. The solutions are obtained using corrections for aspherical earth structure represented by a whole mantle shear velocity model SH8/U4L8 of Dziewonski and Woodward (1992, Acoustical Imaging , Plenum Press, pp. 785–797). A new model of anelastic attenuation of Durek and Ekstrom (1994, EOS, Trans. Am. Geophys. Union, Spring Meet. Suppl. , 75: 83) is used to predict the decay of the waveforms.

Centroid-moment tensor solutions for April–June 1994

Centroid-moment tensor solutions are presented for 187 earthquakes that occurred during the second quarter of 1994. The solutions are obtained using corrections for aspherical Earth structure represented by a whole mantle shear velocity model SH8/U4L8 of Dziewonski and Woodward (Acoustical Imaging, 1992, Vol. 19, pp. 785–797). A new model of anelastic attenuation of Durek and Ekstrom (Eos, 1994, 75: 83) is used to predict the decay of the waveforms.

Centroid-moment tensor solutions for April–June 1991

Centroid-moment tensor solutions are presented for 169 earthquakes that occurred during the second quarter of 1991. The solutions are obtained using corrections for aspherical Earth structure.

Centroid-moment tensor solutions for April–June 1992

Abstract Centroid-moment tensor solutions are presented for 245 earthquakes that occurred during the second quarter of 1992. The solutions are obtained using corrections for aspherical Earth structure represented by a whole mantle shear velocity model SH8/U4L8 of Dziewonski and Woodward. The solution for an earthquake under Mindanao, Philippines, on 9 May represents the 10 000th event in the CMT catalogue.