ABSTRACT. Background. Jaundice in near-term and term newborns is a frequent diagnosis that may prompt hospital readmission in the first postnatal week. Hyperbilirubinemia, when excessive, can lead to potentially irreversible bilirubin-induced neurotoxicity. Predischarge risk assessment (at 24 -72 hours of age) for subsequent excessive hyperbilirubinemia is feasible by a laboratory-based assay of total serum bilirubin (TSB).Hypothesis. Noninvasive, transcutaneous, point-ofcare measurement of transcutaneous bilirubin (TcB) predischarge by multiwavelength spectral analysis, using a portable BiliCheck device (SpectRx Inc, Norcross, GA), is clinically equivalent to measurement of TSB in a diverse, multiracial term and near-term newborn population and predictive of subsequent hyperbilirubinemia.Methodology. We evaluated a hand-held device that uses multiwavelength spectral reflectance analysis to measure TcB (BiliCheck). The study population (490 term and near-term newborns) was racially diverse (59.1% white, 29.5% black, 3.46% Hispanic, 4.48% Asian, and 3.46% other) and was evaluated at 2 separate institutions using multiple (11) devices. The postnatal age ranged from 12 to 98 hours and the ranges of birth weights and gestational ages were 2000 to 5665 g and 35 to 42 weeks, respectively. All transcutaneous evaluations were performed contemporaneously and paired with a heelstick TSB measurement. All TSB assays were performed by high performance liquid chromatography, as well as by diazo dichlorophenyldiazonium tetrafluoroborate techniques.Results. TSB values ranged from .2 to 18.2 mg/dL (mean ؎ standard deviation: 7.65 ؎ 3.35 mg/dL). The overall correlation of TSB (by high performance liquid chromatography technique) to TcB (by BiliCheck devices) was linear and statistically significant (r ‫؍‬ .91; r 2 ‫؍‬ .83; TcB ‫؍‬ .84; TSB ‫؍‬ ؉.75; standard error of regression line ‫؍‬ 1.38; P < .001; n ‫؍‬ 490 infants; 1788 samples). Similar regression statistics were evident in subset populations categorized by race (white: r ‫؍‬ .91 [n ‫؍‬ 289 infants]; black: r ‫؍‬ .91 [n ‫؍‬ 145 infants]) as well as by gestation (term: r ‫؍‬ .91 [n ‫؍‬ 1625 samples]; near-term: r ‫؍‬ .89 [n ‫؍‬ 163 samples]). Intradevice precision was determined to be .59 mg/dL (2-3 measurements per infant with 1 device; n ‫؍‬ 210 infants; 510 samples in a separate subset). Interdevice evaluation of 11 devices determined the precision to be .68 mg/dL (2-4 devices used for measurements per patient).In 23 of 419 of the study population infants who were in the 24-to 72-hour age range, the predischarge TSB values designated them to be at high risk for subsequent excessive hyperbilirubinemia (above the 95th percentile track on the hour-specific bilirubin nomogram). For these infants, the paired BiliCheck TcB values were all above the 75th percentile track (negative predictive value ‫؍‬ 100%; positive predictive value ‫؍‬ 32.86%; sensitivity ‫؍‬ 100%; specificity ‫؍‬ 88.1%; likelihood ratio ‫؍‬ 8.43).Conclusions. Our data demonstrate the accuracy and reproducibil...

A simple yet effective method (iso-density percoll centrifugation) has been developed for consistently preparing isolated rat liver parenchymal cells with over 98% initial viability. The method has been applied to cells isolated by a variety of collagenase digestion techniques. This procedure involves the low-speed centrifugation (50 X g) of the initial cell suspension through a percoll medium having a density of 1.06 g/ml and results in the separation of single and viable parenchymal cells from cell aggregates, debris, and nonparenchymal cells. The enriched parenchymal cells have been shown to be superior to untreated cells by a number of criteria including: preparation homogeneity, cell morphology, maintenance of cytochrome P-450, hormonal responsiveness (measured by the induction of tyrosine aminotransferase after treatment with glucagon or dexamethasone, or both), plasma membrane integrity (determined by both trypan blue exclusion and leakage of glutamic-oxaloacetic transaminase), and the DNA repair capability after treatment with benzo[a]pyrene or 2-acetylaminofluorene.

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