Clinical approach to the analysis of causes of death in the first two years of life of very-low-birthweight infants in a multicentre setting

Mortality in the first 2 years of 634 very-low-birthweight infants admitted to eight neonatal intensive care units in Italy, and the factors associated with the net probability of death from each cause, were studied by means of the Cox proportional hazard model. A clinical classification of the causes of death was used. Overall mortality was 33.7% (intercentre range 12.6-52.9%). The highest cause-specific mortality rates were observed for respiratory problems, intra-ventricular haemorrhage (IVH) and infections (14.5%, 6.3% and 5.7% respectively). The leading causes of death were respiratory problems and IVH in the first week of life, infections from the second week up to the end of the first month, and bronchopulmonary dysplasia (BPD) afterwards. Birthweight < 1000 g, gestational age < 30 weeks, absence of spontaneous respiratory activity, unknown body temperature and pH < 7.20 at admission were associated with death from respiratory problems and IVH. Male sex, birthweight < 1000 g and unknown body temperature at admission were associated with death from BPD. Mortality from infections was higher in one centre; no other differences emerged among the eight NICUs. The classification of the causes of death employed and the use of the net probabilities of death appear as practical and useful instruments to study the relationship between specific aspects of medical care and mortality, and to investigate the reasons for differences in performance between neonatal units.     

Differential proteomics via probabilistic peptide identification scores

Relative quantitation is key to enable differential proteomics and hence answer biological questions by comparing samples. Classical approaches involve stable isotope labeling with/without spiked standards. Although stable isotopes may lead to precise results, their application is not straightforward. In Proteomics, 2004, 4, 2333-2351, we proposed an approach where we summed peptide identification scores to derive a semiquantitative abundance indicator. In this study, we combine such an indicator with a statistical test to detect differentially expressed proteins. We demonstrate the effectiveness of this method by using mixtures of purified proteins and human plasma spiked with proteins at low-nanomolar concentrations. The impact of the number of repeated experiments is discussed, and we show that the statistical test we use performs well with two to three repetitions, whereas a classical t-test would require at least four repetitions to achieve the same performance. Typically, 2.5-5-fold changes are detected with 90-95% confidence in human plasma. The method is finally characterized by deriving estimates of its false positive and negative rates. This new characterization is valid for a wider class of methods such as spectrum sampling (Liu, H.; Sadygov, R. G.; Yates, J. R. III. Anal. Chem. 2004, 76, 4193-4201).     

Speech perception, vocabulary, and the development of reading skills in english among Korean- and English-speaking children.

This study examined the roles of speech perception and phonological processing in reading and spelling acquisition for native and nonnative speakers of English in the 1st grade. The performance of 50 children (23 native English speakers and 27 native Korean speakers) was examined on tasks assessing reading and spelling, phonological processing, speech perception, and receptive vocabulary at the start and end of the school year. Korean-speaking children outperformed native English speakers on each of the literacy measures at the start and end of 1st grade, despite differences in their initial phonological representations and processing skills. Furthermore, speech perception and phonological processing were important contributors to early literacy skills, independent of oral language skills, for children from both language groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of rHuEpo on blood transfusions in preterm infants after the fifteenth day of life

Ex vivo T cell depletion of allogeneic grafts is associated with a high (up to 80%) rate of mixed chimerism (MC) posttransplantation. The number of transplanted progenitor cells is an important factor in achieving complete donor chimerism in the T cell depletion setting. Use of granulocyte colony-stimulating factor (G-CSF) peripheral blood allografts allows the administration of large numbers of CD34+ cells. We studied the chimeric status of 13 patients who received allogeneic CD34+-selected peripheral blood progenitor cell transplants (allo-PBPCTs/CD34+) from HLA-identical sibling donors. Patients were conditioned with cyclophosphamide (120 mg/kg) and total-body irradiation (13 Gy in four fractions). Apheresis products were T cell-depleted by the immunoadsorption avidin-biotin method. The median number of CD34+ and CD3+ cells infused was 2.8x10(6)/kg (range 1.9-8.6x10(6)/kg) and 0.4x10(6)/kg (range 0.3-1x10(6)/kg), respectively. Molecular analysis of the engraftment was performed using polymerase chain reaction (PCR) amplification of highly polymorphic short tandem repeat (PCR-STR) sequences in peripheral blood samples. MC was detected in two (15%) of 13 patients. These two patients relapsed at 8 and 10 months after transplant, respectively. The remaining 11 patients showed complete donor chimerism and were in clinical remission after a maximum follow-up period of 24 months (range 6-24 months). These results were compared with those obtained in 10 patients who were treated with T cell-depleted bone marrow transplantation by means of elutriation and who received the same conditioning treatment and similar amounts of CD3+ cells (median 0.45x10(6)/kg; not significant) but a lower number of CD34+ cells (median 0.8x10(6)/kg; p = 0.001). MC was documented in six of 10 patients (60%), which was significantly higher than in the allo-PBPCT/CD34+ group (p = 0.04). We conclude that a high frequency of complete donor chimerism is achieved in patients receiving allo-PBPCT/CD34+ and that this is most likely due to the high number of progenitor cells administered.     

Phonological awareness and reading acquisition in English- and Punjabi-speaking Canadian children.

This study examined whether the same component processes are involved in reading acquisition for native and nonnative speakers of English in the 1st grade. The performance of 88 children was examined on tasks assessing reading skill, phonological processing, and syntactic awareness. Fifty children were native English speakers (L1), and 38 children were from Punjabi-speaking families (ESL). Although measures of word recognition and phonological processing successfully discriminated between average and poor readers, they did not discriminate between the 2 language groups. Analyses of word reading errors revealed similar error patterns for ESL and L1 children, yet different error patterns for average and poor readers. For both L1 and ESL children, reading difficulties appear to be strongly linked with impaired phonological processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)