Can anesthesiologic strategies for caesarean section influence newborn jaundice? A retrospective and prospective study.

RATIONALE AND OBJECTIVES: Neonatal jaundice is a frequent problem in neonatology and can be influenced by many factors. Our study arose from the clinical observation that among all newborns delivered by caesarean section in our center, some had a more intense physiological jaundice. We began by reviewing clinical anesthesiological case-sheets to ascertain whether this difference was linked to the use of different anesthesiologic strategies. We then performed a prospective study on healthy preterm and term newborns to verify this hypothesis. STUDY DESIGN: We retrospectively considered all healthy term newborns with weight > 2,400 g delivered by caesarean section from January 1998 to May 1999. In the prospective studies we included healthy term and preterm newborns consecutively delivered by caesarean section from May 1999 to December 1999. We excluded preterm newborns with gestational age < 31 weeks and with weight < 1,400 g. RESULTS: Both in retrospective and in prospective studies anesthetic agents employed were isoflurane (A), sevoflurane (B), or bupivacaine (C). The statistical comparison of the three groups in retrospective study confirmed the clinical observation: the total bilirubin levels were significantly higher in the isoflurane group than in the sevoflurane group (p = 0.0000) and bupivacaine group (p = 0.0002). Analysis of data from the prospective study on term newborns confirmed our previous results. In preterm infants total bilirubin is statistically higher in group A starting from 96 h postdelivery. CONCLUSIONS: It is likely that anesthetic technique can be included among factors with possible influence on neonatal jaundice.

Cell cycle distribution of cord blood-derived haematopoietic progenitor cells and their recruitment into the S-phase of the cell cycle.

The objective of this study was to evaluate the cycling status of cord blood (CB)-derived colony-forming cells (CFC) and long-term culture-initiating cells (LTC-IC), and their recruitment into the S-phase of the cell cycle. By using the cytosine arabinoside (Ara-C) suicide approach, we found that only small proportions of both CFC and LTC-IC were in the S-phase of the cell cycle. These estimates were confirmed by flow cytometric DNA analysis, which showed that 96 +/- 2% of CB-derived CD34+ cells were in G0/G1 and only 1.6 +/- 0.4% in the S-phase. Staining of CD34+ cells with an antistatin monoclonal antibody, a marker of the G0 phase, indicated that among CD34+ cells with a flow cytometric DNA content typical of the G0/G1 phase 68 +/- 7% of cells were in the G0 phase of the cell cycle. Incubation (24 h) with interleukin 3 (IL-3), recombinant human stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF) significantly increased the proportion of cells in the S-phase for both CFC and LTC-IC without inducing any loss in numbers. Flow cytometric DNA analysis also showed an increase in CD34+ cells in the S-phase upon continuous exposure to these cytokines. Our findings indicate that: (i) very few CB-derived CFC or LTC-IC were in the S-phase of the cell cycle; (ii) a substantial amount of CD34+ cells with a flow cytometric DNA content typical of the G0/G1 fraction was cycling, as found in the G1 phase of the cell cycle; and (iii) 24-h incubation with IL-3, SCF and G-CSF could drive a proportion of progenitor cells into the S-phase without reducing their number. These data might be useful for gene transfer protocols and the ex vivo expansion of CB-derived progenitor cells.

Cord blood-derived hematopoietic progenitor cells: in vitro response to hematopoietic growth factors and their recruitment into the S-phase of the cell cycle.

BACKGROUND AND OBJECTIVES: In the recent years many studies on the expansion of cord blood (CB)-derived progenitor cells have been performed, whereas less information is available on their cycling status. The objective of this study was to evaluate the cycling status of CB-derived colony-forming cells (CFC) and long-term culture-initiating cells (LTC-IC), and their recruitment into the S-phase of the cell cycle in response to a combination of cytokines. DESIGN AND METHODS: CB-derived CFC and LTC-IC were first quantified by standard clonogenic assay and long-term culture, respectively. In a second set of experiments, CB-derived progenitor cells were incubated with interleukin(IL)-3, stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF) and their cell cycle status assessed both by the cytosine arabinoside (Ara-C) suicide approach and by flow cytometric DNA analysis. RESULTS: We found that only small proportions of both CFC and LTC-IC were in the S-phase of the cell cycle. These estimates were confirmed by flow cytometric DNA analysis, which showed that 96% +/- 2% of CB-derived CD34+ cells were in G0/G1 and only 1.6% +/- 0.4% in the S-phase. Staining of CD34+ cells with an anti-statin monoclonal antibody, a marker of the G0 phase, indicated that among CD34+ cells with a flow cytometric DNA content typical of the G0/G1 phase, 68% +/- 7% of cells were in the G0 phase of the cell cycle. Twenty-four hour incubation with IL-3, SCF and G-CSF significantly increased the proportion of cells in the S-phase for both CFC and LTC-IC without inducing any loss in their number. Flow cytometric DNA analysis also showed an increase of CD34+ cells in the S-phase upon continuous exposure to these cytokines. INTERPRETATIONS AND CONCLUSIONS: Our findings indicate that: i) a small number of CB-derived CFC and LTC-IC are in the S-phase of the cell cycle; ii) a substantial number of CD34+ cells with a flow cytometric DNA content typical of the G0/G1 fraction are cycling, as they are found in the G1 phase of the cell cycle; iii) 24-hour incubation with IL-3, SCF and G-CSF can drive a proportion of progenitor cells into the S-phase without reducing their number.

Natural killer cell activity and delivery: possible influence of cortisol and anesthetic agents. A study on newborn cord blood.

The aim of this study was to evaluate the influence of the method of delivery, the level of cord blood lidocaine, and the cortisol concentration on the cord blood natural killer (NK) activity in the full-term healthy newborn. We studied healthy newborns delivered by elective cesarean section without labor under general anesthesia (n = 24), delivered by cesarean section under epidural anesthesia (n = 21), and delivered vaginally with uncomplicated labor (n = 19). The NK cell activity was significantly lower in newborns delivered by cesarean section under epidural anesthesia than it was in the general anesthesia group, while it was similar to the levels found in vaginally delivered newborns. The cortisol concentration was highest in the vaginal delivery group (589.2 +/- 200 mmol/l) and lowest in the general anesthesia group (199.2 +/- 81.9 mmol/l). The mean serum lidocaine concentration was 414.1 +/- 370 microgram/l in the epidural anesthesia group and undetectable in the other groups. In conclusion, our data suggest that the cord blood NK activity was significantly influenced by the method of delivery. This effect could be related to anesthetics given to the mother for general or epidural anesthesia or to the endocrine-metabolic variations observed after different degrees of delivery-related stress. The NK cells being a first-line defense mechanism against viral infections, the results of this study suggest an association with the occurrence of early perinatal infections, especially in preterm infants.