Premature infants born at <25 weeks of gestation may be compromised by currently recommended resuscitation techniques.

AIM: Standard resuscitation guidelines are based on data from a range of gestational ages. We sought to evaluate the effectiveness of our delivery room resuscitation protocol across a range of gestational ages in preterm infants born at <29 weeks. METHODS: We performed an observational study of prospectively collected video recordings of 73 preterm infants. The percentage of bradycardic patients, time to reach target oxygen saturation and the extent of all interventions were compared between three gestational age groups: 22-24 weeks (n = 22), 25-26 weeks (n = 27) and 27-28 weeks (n = 24). RESULTS: Although the same resuscitation protocol was followed for all infants, bradycardic infants born <25 weeks responded poorly and required significantly longer to reach oxygen saturation targets of >70%, >80% and >90% (p < 0.03). They required significantly more interventions and had higher rate of death (p < 0.05) and severe intraventricular haemorrhage (p < 0.03). Significantly lower heart rate and oxygen saturation values were found in infants with intraventricular haemorrhage. CONCLUSION: Current recommendations for resuscitation may fail to achieve timely lung aeration in infants born at the borderline of viability, leading to higher mortality and morbidity. Sustained inflation and delayed cord clamping may be effective alternatives.

Efficacy of FiO2 increase during the initial resuscitation of premature infants < 29 weeks: an observational study.

OBJECTIVE: To evaluate the heart rate (HR) and oxygen saturation (SpO2) at 15-second intervals within 60 seconds after incremental increases of fractional inspired oxygen (FiO2) during resuscitation of infants younger than 29 weeks requiring two different forms of ventilatory support. STUDY DESIGN: Retrospective observational study. METHODS: Forty-three infants were stabilized, 14 by continuous positive airway pressure exclusively (CPAP group), and 29 by positive pressure ventilation (PPV group). Both groups received ventilatory support in a special bed with two cameras enabling the evaluation of all interventions including HR, SpO2, FiO2, positive inflation pressure, and positive end-expiratory pressure values. FiO2 was commenced at 0.30 and titrated in 0.1-0.2 increments every 30-60 seconds. The relationships between the incremental increases of FiO2 and related SpO2 and HR changes were evaluated. RESULTS: Although there was an inverse correlation between initial FiO2 and SpO2 in both groups, a significant positive correlation between the incremental increase of FiO2 and SpO2 changes after 30 seconds was found only in the CPAP group. Only higher initial levels of FiO2 had a positive effect on the improvement in SpO2 in the PPV group. CONCLUSION: The efficacy of FiO2 titration in 0.1-0.2 increments may be attenuated and delayed in extremely preterm infants required PPV during the first 6 minutes of life.

An unusual p53 mutation detected in Burkitt's lymphoma: 30 bp duplication.

Burkitt's lymphomas (BL) are aggressive rapidly growing tumors typified by a high c-myc expression resulting from t(8;14)(q24;q32), t(2;8)(p12;q24) or t(8;22)(q24;q11) translocations. Alterations of the p53 tumor suppressor are also relatively frequent in BL. Several approaches have been adopted for detection of the p53 aberrations such as immunohistochemical analyses, immunoblotting, DNA sequencing, fluorescence in situ hybridization (FISH), and functional assays. We used these methods to characterize the p53 mutation in tumor cells of a 53-year-old male suffering from Burkitt's lymphoma. By immunohistochemical analyses, we detected high levels of the p53 protein in the tumor tissue. Immunoblotting showed a higher molecular weight of the p53 protein overexpressed in the tumor tissues than that of the standard p53 protein. Similarly, the molecular weight of the PCR product prepared by amplification of the tumor p53 cDNA was higher than that of the standard p53 cDNA. Functional analyses of separated alleles in yeast evidently revealed that the tumor p53 protein was transcriptionally non-functional. The yeast colonies expressing this p53 variant possessed a unique phenotype in that they were red with many white spots on their surface. Sequencing of the tumor cDNA revealed a duplication of the 30 bp region of the p53 gene (g.12155_12184dup30) leading to a repeat of 10 amino acids (Pro-77 to Ala-86) in the p53 protein. Further analyses showed that the mutation was unstable in yeast cells. The FISH analyses did not confer loss of the p53-specific locus 17p13.