Early regional response of apoptotic activity in newborn piglet brain following hypoxia and ischemia.

Responses of selected neuroregulatory proteins that promote (Caspase 3 and Bax) or inhibit (Bcl-2, high Bcl-2/Bax ratio) apoptotic cell death were measured in the brain of piglets subjected to precisely controlled hypoxic and ischemic insults: 1 h hypoxia (decreasing FiO2 from 21 to 6%) or ischemia (ligation of carotid arteries and hemorrhage), followed by 0, 2 and 4 h recovery with 21% FiO2. Protein expression was measured in cortex, hippocampus and striatum by Western blot. There were no significant differences in expression of Caspase-3 between sham operated, hypoxic and ischemic groups. There were significant regional differences in expression of Bcl-2 and Bax in response to hypoxia and ischemia. The changes in Bcl-2/Bax ratio were similar for hypoxia and ischemia except for striatum at zero time recovery, with ischemia giving lower ratios than hypoxia. The Bcl-2/Bax ratio was also lower for the striatum than for the other regions of the brain, suggesting this region is the more susceptible to apoptotic injury.

A methodological approach to developing an assessment procedure for testing the neurobehavioral maturity of preterm infants.

Using data from 179 preterm infants, a neurobehavioral maturity assessment was developed by using a process in which clusters characterized by conceptual coherence and face validity were systematically subjected to statistical analyses designed to test whether they also had high test-retest reliability, statistical cohesion, and developmental validity. The psychometric soundness of the test items was made a precondition for their inclusion into the assessment procedure. Also tested were cluster redundancy, as well as the impact of gestational and conceptional age, and of postbirth influences on the functions tested. 8 dimensions of neurobehavioral functioning were found to be stable with a test-retest reliability of at least .6 or higher on 2 consecutive days, nonredundant and developmentally valid. They were: Active Tone/Motor Vigor, Alertness and Orientation, Excitation Proneness, Inhibition Proneness, Scarf Sign, Popliteal Angle, Maturity of Vestibular Response, and Vigor of Crying.

Changes in popliteal angle measurement in infants up to one year of age.

The purpose of this study was to determine trends in the changes of the popliteal angle in 130 normal infants between one day and 12 months of age, for use in assessing infants with possible neuromuscular pathology. Using a 360 degree goniometer, the popliteal angle was measured with the hip held at 90 degree flexion, to indicate hamstring-muscle tightness. Limitation of knee extension was also measured with the hip extended (HEKE angle) to indicate capsular tightness. Both the popliteal and HEKE angle measurements showed greatest limitation of knee extension at birth, which decreased until eight months of age, when most infants showed no limitation. A highly significant negative correlation was found between age and mean popliteal and HEKE angles.