Association Between Hypoglycemia and the Occurrence of Early Onset Sepsis in Premature Infants.

BACKGROUND: We examined the association between hypoglycemia and the occurrence of early onset sepsis (EOS) in premature infants admitted to the neonatal intensive care unit (NICU). METHODS: We included infants discharged from 358 NICUs between 1997 and 2020 with gestational age <34 weeks, ≥1 culture collected in the first 3 days of life, and ≥1 serum glucose value recorded on the day of or day prior to culture collection. We used multivariable logistic regression and inverse probability weighting (IPW) and constructed models for three definitions of hypoglycemia: American Academy of Pediatrics (AAP), Pediatric Endocrine Society, and a definition based on neurodevelopmental studies. We performed subgroup analysis in EOS episodes caused by Gram-negative and Gram-positive organisms. RESULTS: Of the 62,178 infants and 64,559 cultures that met study inclusion criteria, 739 (1%) cultures were positive. The median (25th, 75th percentile) glucose value was 75 mg/dL (50, 106) on the day of or day prior to a positive culture versus 70 mg/dL (50, 95) on the day of or day prior to a negative culture. We found that hypoglycemia was not associated with the occurrence of EOS for all organisms and Gram-positive organisms, whereas there was a small but significant association between the lower AAP glucose cutoff value and EOS due to Gram-negative organisms (logistic regression: risk difference [RD] 0.24% [95% CI, 0.01-0.47]; IPW: RD 0.22% [95% CI, 0.00-0.43]). CONCLUSIONS: Hypoglycemia may be an early marker of EOS, particularly in episodes caused by Gram-negative organisms and when using a stricter definition of hypoglycemia.

Association and in silico assignment of sequences from turkey BACs.

Bacterial artificial chromosomes (BACs) provide an important resource in genetic mapping. An initial set of BACs corresponding to microsatellite markers in the turkey (Meleagris gallopavo) was isolated from the CHORI-260 turkey BAC library. The selected markers were distributed on both macro- and microchromosomes and included a genetically unlinked marker. End sequences were obtained for a subset of the recovered BACs and compared to the chicken whole genome sequence. Close association of the turkey BAC-end sequences and original marker sequences was generally conserved in the chicken genome. Gene content of the turkey BACs is predicted from the comparative sequence alignments.

Host shifts and the beginning of signal divergence.

Divergence between populations adapting to different environments may be facilitated when the populations differ in their sexual traits. We tested whether colonizing a novel environment may, through phenotypic plasticity, change sexual traits in a way that could alter the dynamics of sexual selection. This hypothesis has two components: changes in mean phenotypes across environments, and changes in the genetic background of the phenotypes that are produced -- or genotype x environment interaction (G x E). We simulated colonization of a novel environment and tested its effect on the mating signals of a member of the Enchenopa binotata species complex of treehoppers (Hemiptera: Membracidae), a clade that has diverged in a process involving host plant shifts and signal diversification. We found substantial genetic variation and G x E in most signal traits measured, with little or no change in mean signal phenotypes. We suggest that the expression of extant genetic variation across old and novel environments can initiate signal divergence.