Have the boundaries of the 'grey zone' of perinatal resuscitation changed for extremely preterm infants over 20 years?

AIM

To determine the boundaries of the grey zone of discretionary resuscitation over the past 20 years.

BACKGROUND

As the likelihood of survival improves over time, the BW- and GA-specific boundaries of discretionary nonresuscitation should fall.

HYPOTHESIS

Between 1988 and 2008 reductions in BW- and GA-specific mortality would drive a parallel reduction in BW and GA boundaries of discretionary resuscitation.

METHODS

We determined the likelihood of resuscitation and survival to NICU discharge for all infants born <700 g or <26 gestational weeks from 1988 to 2008. In addition, for 1988, 1993, 1998, 2003 and 2008, we determined the BW and GA for the 10 smallest infants who were resuscitated, and the 10 largest infants who were not resuscitated. We excluded any infant born with congenital anomaly.

RESULTS

Mortality fell from 80% in 1988 to 28% in 2008, and as expected, the percentage who were resuscitated rose from 63% in 1988-93 to 95% in 2004-2008. However, unexpectedly, over the 20-year study period, the smallest infants who were resuscitated despite extreme immaturity did not change (450-550 g and 23-24 weeks) and the largest infants not resuscitated did not change (600-700 g and 23-24 weeks.

CONCLUSION

Neither the BW nor GA boundaries of the grey zone of discretionary resuscitation have fallen over the past 20 years. Factors guiding resuscitation at the border of viability are complex and incompletely understood.

Effect of glycation of high density lipoproteins on their physicochemical properties and on paraoxonase activity

We investigated the effect of incubation of high density lipoprotein (HDL) under hyperglycaemic conditions on lipid composition, physicochemical properties and activity of paraoxonase (PON), a calcium-dependent enzyme associated with HDL that contributes to the antiatherogenicity of this lipoprotein. HDL incubated for three days with various glucose concentrations (0-100 mM) had significant increases in thiobarbituric acid-reactive substances (TBARS) and conjugated dienes with respect to control HDL. These results suggest that lipid peroxidation accompanies HDL glycation in vitro. The susceptibility to lipid peroxidation was higher in HDL isolated from subjects with low HDL-paraxonase activity with respect to subjects with higher HDL-PON activity. The lipid compositional changes were associated with modifications of apoprotein conformation as shown by the red-shifted position of the maximum emission of tryptophan in treated HDL. The decrease in the Gp (generalized polarization) value and the red-shifted position of the maximum emission of Laurdan incorporated in treated HDL demonstrate modifications of order and polarity with respect to control HDL. The negative correlation established between the Gp value and TBARS demonstrates that the modifications in molecular order are likely related to the increase in lipid peroxidation products. The activity of paraoxonase was significantly decreased in HDL incubated at 37 degrees C; a greater decrease occurred in the presence of 50 mM and 100 mM glucose. This study demonstrates modifications of lipid composition, apoprotein conformation and physicochemical properties of HDL incubated in the presence of glucose. These modifications affect the activity of HDL-associated paraoxonase. The physicochemical properties of lipoproteins play a regulatory role in lipoprotein function. The modification of order and polarity of glycated HDL and the alterations in paraoxonase activity could potentially contribute to the accelerated atherosclerosis in diabetic patients.

Tumor angiogenesis and p53 mutations: prognosis in head and neck cancer

OBJECTIVES

To assess how p53 gene mutations and microvessel density (MVD) may be used as prognostic markers for the study and management of head and neck squamous cell carcinomas and to investigate putative associations between p53 gene mutations and MVD and the relationship of these factors to tumor response to radiotherapy and/or chemotherapy at 6 weeks.

PATIENTS AND DESIGN

Thirty-nine patients with squamous cell carcinoma of the head and neck, stages I to IV, who were examined at Rush-Presbyterian-St Luke's Medical Center, Chicago, Ill, and its affiliated hospitals between 1993 and 1995 were monitored. Mutations in the p53 gene were identified by microdissection of tumor cells on frozen sections, followed by single-strand conformation polymorphism analysis of the products of polymerase chain reaction amplification of exons 5 to 9. The microvessels were immunostained with monoclonal antibodies to factor VIII and/or CD31. Microvessel counts were done by 2 investigators blinded to each other's counts and to the p53 gene status. Intratumoral or peritumoral microvascular "hot spots" were assessed and counts were done with an ocular grid in 3 x 200 fields of hot spots by each investigator. The mean of the highest values was considered. Statistical analysis was done with the Wilcoxon rank sum test, the log-rank test, and proportional hazard models.

RESULTS

Of the 39 patients, 13 had mutations in exons 5 to 9. Mutations in the p53 gene were associated with unfavorable overall (P=.003) and disease-free (P=.02) survival. A strong inverse relationship was seen between MVD and p53 mutations (P=.01). No statistically significant relationship was seen between mean MVD and overall and disease-free survival. The response to therapy differed significantly (P=.03) by p53 mutations, whereas there was no statistical significance with MVD counts.

CONCLUSION

In this study a strong inverse relationship was seen between MVD and p53 mutations. p53 Mutations in exons 5 through 9 were associated with unfavorable survival, whereas MVD showed no association with survival.

[Postoperative septic complications in patients operated on for thoracic neoplasms]

The authors executed a prospective clinic study evaluating, whether at the admittance or after surgery, the immunity status of 30 patients with a thoracic neoplasm, admitted to Department of Thoracic Surgery, I School of Medicine, Naples. Only 21 of them, immunodepressed at the admittance, were accepted to trial and assigned respectively to A Group destined to surgery (10 patients) and to B check Group (11 patients). In the A Group the effectiveness of the immunotherapy was valued in the prophylaxis and in the postoperative septic complications' therapy. The global incidence of those complications was of 6 cases, of which 10% only in A Group and 45% in B Group. In the operated patients the septic complications had few repercussions on general status and were rapidly and totally dominated in strict correlation with an adequate immunoreconstitution.