The nucleotide sequence of the C-terminal region of the recE gene of the Rac prophage of Escherichia coli K-12 reveals the presence of a partially overlapping reading frame we call recT. Deletion mutations show that recT is required for the RecE pathway of conjugational recombination. By cloning recT with a plasmid vector compatible with pBR322, we showed by cis-trans tests that the portion of the recE gene encoding ExoVIII DNA nuclease activity is also required for RecE pathway conjugational recombination. The recT gene can replace the redB gene of lambda for recA-independent plasmid recombination. A Tn10 insertion mutation previously thought to be in recE is located in recT and is renamed recT101::Tn10. Discrepancies between the molecular mass estimates of wild-type ExoVIII protein determined from mobility in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and calculated from the predicted amino acid sequence are discussed. The hypothesis that wild-type ExoVIII protein results from fusion of RecE and RecT proteins is disproved genetically, thus supporting a previous hypothesis that the discrepancies are due to abnormal protein mobility in SDS-PAGE. A computer-performed scan of the bacteriophage nucleotide sequence data base of GenBank revealed substantial similarity between most of recE and a 2.5-kb portion of the b2 region of lambda. This suggests interesting speculations concerning the evolutionary relationship of lambda and Rac prophages.

Background: Little is known about the glucose concentrations at and after birth of infants delivered by caesarean section (CS), when compared with infants born vaginally (VD).Aim: To compare venous cord blood glucose concentrations of term infants born after elective CS to infants born by VD. We studied the null hypothesis that mode of delivery does not affect neonatal blood glucose values. Methods:We compared cord blood glucose concentrations in healthy term infants born after VD (n = 16) or by elective CS (n = 21). Glucose concentrations were obtained immediately at birth from the umbilical cord. Kruskal-Wallis was used to compare glucose concentrations and demographic variables between the groups.Results: Gestational age was 39.6 ± 0.8 weeks in VD group vs. 38.7 ± 0.9 weeks in CS group, and birthweight was 3359 ± 494 vs. 3500 ± 528 g. Cord blood glucose concentration was higher in VD (81.3 ± 16.9 mg ⁄ dL) than CS infants (70.3 ± 9.7 mg ⁄ dL, p = 0.039). The change in blood glucose concentration over the first 2-h of life differed significantly between the two groups, being an increase in CS versus a decrease in VD infants ()3.5 ± 15.2 vs. )15.4 ± 24.6 mg ⁄ dL, p = 0.013).Conclusions: Glucose concentrations in VD infants are higher than in infants born by elective CS without labour.

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The neonatal period is considered to be essential for neurodevelopment and wellbeing throughout the life span, yet little is known about brain-behavior relationships in the neonatal period. The aim of this study was to evaluate the association between neonatal sensory-motor regulation and white-matter (WM) integrity of major fiber tracts in the neonatal period. We hypothesized that WM integrity of sensory-motor systems would predict neurobehavioral maturation during the first month of life. Forty-nine premature neonates underwent magnetic-resonance-imaging at term. Diffusion-tensor-imaging analysis was performed in major WM tracts along with repeated neonatal neurobehavioral evaluations assessing sensory reactivity and motor regulation. Difficulties in one or more behavioral sub-category, mostly in auditory and visual attention, hypotonicity and jitteriness, were documented in 78.3% infants at term. Sixty-six percent of infants experienced difficulties, mostly in auditory attention, head-neck control, hypotonicity and motor asymmetry, at 44 weeks. Attention difficulties were associated with reduced integrity of cerebral and superior cerebellar peduncles; while tonicity was associated with reduced integrity of the corpus-callosum and inferior-posterior tracts. Overall, results showed that early maturing tracts were related with the degree of typicality of sensory reactivity status while late maturing tracts were related with the degree of typicality of tonic regulation. WM integrity and maturation factors explained 40.2% of the variance in neurobehavior at 44 weeks. This study suggests that in preterm neonates, deviant sensory-motor reactivity can be detected very early in development in manners that are related to lower integrity/maturational level of early and late maturing fiber tracts.