Respiratory health outcomes 1 year after admission with severe lower respiratory tract infection.

Severe lower respiratory infection (LRI) is believed to be one precursor of protracted bacterial bronchitis, chronic moist cough (CMC), and chronic suppurative lung disease. The aim of this study was to determine and to describe the presence of respiratory morbidity in young children 1 year after being hospitalized with a severe LRI. Children aged less than 2 years admitted from August 1, 2007 to December 23, 2007 already enrolled in a prospective epidemiology study (n = 394) were included in this second study only if they had a diagnosis of severe bronchiolitis or of pneumonia with no co-morbidities (n = 237). Funding allowed 164 to be identified chronologically, 131 were able to be contacted, and 94 agreed to be assessed by a paediatrician 1 year post index admission. Demographic information, medical history and a respiratory questionnaire was recorded, examination, pulse oximetry, and chest X-ray (CXR) were performed. The predetermined primary endpoints were; (i) history of CMC for at least 3 months, (ii) the presence of moist cough and/or crackles on examination in clinic, and (iii) an abnormal CXR when seen at a time of stability. Each CXR was read by two pediatric radiologists blind to the individuals' current health. Results showed 30% had a history of CMC, 32% had a moist cough and/or crackles on examination in clinic, and in 62% of those with a CXR it was abnormal. Of the 81 children with a readable follow-up X-ray, 11% had all three abnormal outcomes, and 74% had one or more abnormal outcomes. Three children had developed bronchiectasis on HRCT. The majority of children with a hospital admission at <2 years of age for severe bronchiolitis or pneumonia continued to have respiratory morbidity 1 year later when seen at a time of stability, with a small number already having sustained significant lung disease.

Intended plans for breastfeeding duration: a simple tool to predict breastfeeding outcome.

UNLABELLED: Prenatal intended duration of breastfeeding has been shown to be a powerful predictor of breastfeeding initiation and duration. This provides a tool to establish the risks for short duration of breastfeeding. CONCLUSION: It is necessary to identify the factors that influence mothers' plans, and to find means to intervene effectively.

Variations in bronchiolitis management between five New Zealand hospitals: can we do better?

OBJECTIVES: To determine the current management of bronchiolitis by five major New Zealand hospitals and to identify areas for improvement. METHODS: Lists of infants under 1 year of age admitted with bronchiolitis during 1998 were obtained from the casemix offices of the five largest New Zealand hospitals with paediatric services. Hospital records from a random sample of these admissions were reviewed. RESULTS: Out of the 409 infants admitted overnight, 8% had been born less than or=32 weeks gestation and 53% were aged younger than 6 months. Overall, 59% received oxygen, 21% had nasogastric fluids, 22% had intravenous fluids, 34% were prescribed antibiotics, 42% received bronchodilators and 60% had a chest radiograph. Respiratory secretions were collected for viral studies from 58% of infants and, in 59%, respiratory syncytial virus was detected. Significant variations in management were detected between hospitals. The overall proportion of infants requiring oxygen, intravenous or nasogastric fluids (65%) was significantly higher than that found in a 1986-1988 Christchurch study where only 25% received one or more of these interventions (P < 0.001). CONCLUSIONS: Opportunities exist to rationalize bronchiolitis management in New Zealand with potential cost savings, particularly by reducing the number of chest radiographs and prescribing of unnecessary antibiotics and bronchodilators.

Palivizumab prophylaxis of respiratory syncytial virus infection in high-risk infants.

Palivizumab prophylaxis significantly reduces hospitalization for respiratory syncytial virus (RSV) disease in preterm infants. However, palivizumab is very expensive. Data from a New Zealand cost-effectiveness analysis were considered by representatives of the Infectious Diseases and Immunisation, Fetus and Newborn, and Respiratory Committees of the Paediatric Society of New Zealand. Prophylaxis in all high-risk groups was associated with net cost. The consensus panel recommends that the priority for palivizumab be given to babies discharged on home oxygen with chronic lung disease, followed by babies born at 28 weeks or less gestation.

Cost-effectiveness of palivizumab in New Zealand.

OBJECTIVE: To establish the preterm infant hospitalization risks from respiratory syncytial virus (RSV) in New Zealand and the net cost per hospitalization averted by palivizumab. METHODS: The 437 infants born < 32 weeks' gestation in 1997 and treated at five major neonatal units were identified. Subsequent admissions during the next 2 years for bronchiolitis, pneumonia and croup were tracked, and information collected on RSV tests performed. Data on the length of stay and hospital costs were used to calculate the potential net cost per hospitalization averted associated with the use of palivizumab and the number needed to treat (NNT) to prevent one hospitalization. RESULTS: Estimated RSV readmission risk before 1 year corrected age in infants < 32 weeks' gestation discharged home on oxygen, and those " 28 weeks' gestation, or between 29 and 31 weeks' gestation with or without chronic lung disease was 42%, 23%, 19%, 10% and 8%, respectively. The NNT with palivizumab to prevent one hospitalization ranged from six to 26 across subgroups. Mean (range) net cost per hospitalization averted was 60,000 New Zealand dollars ($28,000-$166,700). In no subgroup would prophylaxis result in net cost saving. Prophylaxis for all NZ infants " 28 weeks' gestation would cost approximately $1,090,000 net and prevent 29 hospitalizations annually, being equivalent to $37,000 net per hospitalization averted, with eight infants treated to prevent one hospitalization. Alternative assumptions about cost and efficacy failed to alter these findings. CONCLUSION: If value is placed on preventing morbidity, the priority groups for palivizumab prophylaxis are preterm infants discharged home on oxygen, followed by preterm infants of 28 weeks' gestation or less.

The impact of pacifier use on breastfeeding: a prospective cohort study.

OBJECTIVES: To determine the predictors of pacifier use during the first year of life and to assess the influence of pacifier use on the duration of breastfeeding. METHODOLOGY: A prospective cohort study was conducted. Three hundred and fifty mother-infant pairs were followed to 1 year of age to determine the impact of the use of a pacifier on the duration of breastfeeding. RESULTS: A cohort of 441 mothers were enrolled and 79% participated. Ninety four per cent were followed up to 1 year. Daily pacifier use was associated with early cessation of breastfeeding (risk ratio (RR) 1.71; 95% confidence interval (95%CI) 1.29, 2.28) and a reduced duration of full breastfeeding (adjusted (adj.) RR 1.35; 95%CI 1.05, 1.74). Finger sucking was not associated with a reduced duration of breastfeeding (RR 1.05; 95%CI 0.81, 1.37). Pacifier use less than daily was not associated with a change in duration of breastfeeding (RR 1.02; 95%CI 0.75, 1.39). Most mothers commenced the use of a pacifier within the first month. Multiple logistic regression analysis found that the use of a pacifier was associated with male gender (adj. RR 1.97; 95%CI 1.23, 3.13), maternal smoking in pregnancy (adj. RR 2.23; 95%CI 1.01, 4.95), and low maternal confidence with breastfeeding (adj. RR 2.70; 95%CI 1.48, 4.93). CONCLUSIONS: Daily pacifier use is associated with a reduced duration of breastfeeding. Less frequent pacifier use does not reduce the duration of breastfeeding.

Isolation, characterization, expression and functional analysis of the zebrafish ortholog of MEN1.

Mutations in the MEN1 gene lead to an autosomal dominant disorder, multiple endocrine neoplasia type 1 (MEN1), which is characterized by tumors of the parathyroid, entero-pancreatic neuroendocrine, and pituitary tissues. The protein encoded by MEN1, 610-amino acid menin, resides primarily in the nucleus and binds to the transcription factor JunD, resulting in the repression of JunD-induced transcription. We report here a detailed characterization of the zebrafish men1 gene and its full-length (2551 nt) transcript, encoding a 617-amino acid protein with 67% identity and 80% similarity to human menin. Of the 81 missense mutations and in-frame deletions reported in MEN1 patients, 72 occur in residues that are identical in zebrafish, suggesting the importance of the conserved regions. The zebrafish men1 gene maps 61 cM from the top of linkage group 7 (LG7), a region that appears to show conserved synteny to the MEN1 loci at human 11q13. A 2.7-kb men1 message is detected at all stages of zebrafish development analyzed, from one-cell embryos to adult fish. Whole-mount in situ hybridization showed ubiquitous distribution of men1 message in zebrafish embryos at cleavage, blastula, gastrula, and early segmentation stages, with relatively abundant expression in blood cell progenitors (24 h post fertilization) and mesenchymal tissues (48 h post fertilization) at later stages. Zebrafish menin binds both human and mouse JunD, and represses JunD-induced transcription, indicating that the JunD-binding ability of menin is evolutionarily conserved.

Studying vascular development in the zebrafish.

The zebrafish, a genetically accessible vertebrate with an externally developing, optically clear embryo, is ideally suited for in vivo functional dissection of the embryonic development of the circulatory system. Here, we review the advantages of the zebrafish as a model system for studying vascular development, and describe genetic and experimental tools, methods and resources that have been developed to exploit these advantages. We also discuss briefly how some of these tools and methods can be brought to bear on problems of relevance to human health.

Promoter activity of the zebrafish bhikhari retroelement requires an intact activin signaling pathway.

We have investigated mesoderm induction in zebrafish employing the zebrafish LTR-retroelement bhikhari (bik). bik elements are transcribed in all early mesendodermal cells. This expression pattern is generated by a promoter located in the U3 region of the LTR. We show that bik is activated through the activin/Vg1 signaling pathway in an immediate early fashion. This activation critically depends on a sequence motif that occurs among others also in the Xenopus Mix2 activin response element (ARE). It has been shown that the Mix2 ARE binds FAST- 1, which complexes with Smad proteins to form a multi-protein complex. We confirm that also the bik ARE can be bound by FAST-1 in vitro. In animal cap experiments we demonstrate that this binding site is required for activin-induced transcriptional activation mediated by FAST and Smad-type proteins.

Factors influencing infant feeding practices of mothers in Vancouver.

This study describes factors influencing infant feeding choices of 434 mothers with 9-month-old infants in Vancouver. Consistent with Social Cognitive Theory, both internal personal and socio-environmental factors influence infant feeding choices. Mothers attributed the choice to breastfeed primarily to personal choice, whereas the choice to formula feed was attributed to socio-environmental factors. Among mothers who breastfed < 3 months, the choice to wean was primarily attributed to concern for baby's nutrition; compared to returning to work, concern about milk supply and concern for baby's nutrition among those who breastfed > or = 3 to < 6 months; and returning to work and personal choice among those who breastfed > or = 6 months. Among Caucasian mothers, the choice to wean was primarily attributed to returning to work, compared to concern for baby's nutrition among non-Caucasian mothers. Initiatives to facilitate further advances in breastfeeding promotion could address three areas: 1) prenatal intentions, 2) early postpartum concerns, and 3) later issues surrounding returning to work and infant nutrition.

A zebrafish homolog of the serum response factor gene is highly expressed in differentiating embryonic myocytes.

Serum response factor (SRF) was identified as an activity binding upon serum stimulation of HeLa cells to a motif known as the serum response element in the c-fos promoter. This element is also found in the regulatory regions of many muscle-specific genes. We have characterized srf expression during early zebrafish embryogenesis. In addition to low-level expression in many or even all cells, elevated levels of srf RNA and protein are transiently expressed in skeletal muscle lineages during their differentiation.

The establishment and duration of breastfeeding. Part 1: Hospital influences.

Most New Zealand mothers initiate breastfeeding in hospital, but many continue for only a relatively short time. Focus group discussions with mothers and health care workers on their perceptions of important factors influencing the duration of breastfeeding indicated many negative initial hospital experiences. Specific concerns included overworked staff; lack of health care workers' skills, particularly in helping infants to latch on; inconsistent advice; noise and embarrassment in four bedded rooms; and the impact of changes in the provision of maternity services and funding.

The establishment and duration of breastfeeding. Part 2: Community influences.

Most New Zealand mothers initiate breastfeeding in hospital, but many continue for only a relatively short time. This paper reports on mothers' and health care workers' perceptions of important community factors influencing the duration of breastfeeding. Data collection was by focus group discussions. The results indicate that some mothers have specific plans regarding the duration of breastfeeding but many do not. The importance of practical help, realistic role expectations, community acceptance especially amongst men, adequate maternity leave, and help for those returning to work is emphasised. Conflicting opinions exist about the difficulties of introducing older infants to bottles.

Prevalence and impact of chronic childhood conditions in Auckland, New Zealand.

OBJECTIVE: To establish the prevalence of specific chronic conditions of childhood in the Auckland area and to quantify resource use by these children. METHODOLOGY: Estimates were made from available registry data and published data sources of the population of children with selected chronic conditions resident in the Auckland Area Health Board area. Resource use data were extracted for admissions to Auckland public hospitals and from providers of community based technology services. RESULTS: The largest community prevalence groups are those with asthma, intellectual handicap, congenital heart disease and epilepsy. Children aged 0-14 with chronic conditions accounted for at least 14,340 hospital days stay in Auckland in 1992 at an estimated minimum cost of $7.9 million. Over 200 children are dependent on technological aids at home. CONCLUSIONS: There are sparse data on the numbers and needs of children with chronic conditions in the population. A non-categorical approach which crosses disease entities may be the best method of meeting common needs.

Breastfeeding and weaning practices in Vancouver.

This study describes infant feeding practices in Vancouver during the first nine months after birth, as compared with the Canadian Pediatric Society (CPS) guidelines and results of studies from other parts of Canada. Information on feeding practices and family background was obtained from parents of 434 nine-month-old infants by questionnaire and diet history. The overall rate of breastfeeding initiation was 82.9%, but this differed significantly between Caucasian (91.6%) and non-Caucasian (56.8%) mothers. Introduction of solid foods occurred at ages consistent with CPS recommendations, but only 18.2% of mothers still breastfed at nine months' postpartum. Breastfeeding practices were significantly associated with the mothers' marital status, education and family income. Women who were single, had no post-secondary education, or had a family income of less than $30,000 were least likely to breastfeed, or to do so for longer durations. The development of educational and support systems to encourage longer breastfeeding among different ethnic and socioeconomic groups should be a priority for infant nutrition initiatives.

Mutational analysis of a conserved motif of Agrobacterium tumefaciens VirD2.

The VirD2 polypeptide from Agrobacterium tumefaciens, in the presence of VirD1, introduces a site- and strand-specific nick at the T-DNA borders. A similar reaction at the origin of transfer (oriT) of plasmids is essential for plasmid transfer by bacterial conjugation. A comparison of protein sequences of VirD2 and its functional homologs in bacterial conjugation and in rolling circle replication revealed that they share a conserved 14 residue segment, HxDxxx(P/u)HuHuuux [residues 126-139 of VirD2; Ilyina, T.V. and Koonin, E.V. (1992) Nucleic Acids Res. 20, 3279-3285]. A mutational approach was used to test the role of these residues in the endonuclease activity of VirD2. The results demonstrated that the two invariant histidine residues (H133 and H135) are essential for activity. Mutations at three sites, histidine 126, aspartic acid 128 and aspartic acid 130, that are conserved in a subfamily of the plasmid mobilization proteins, led to the loss of VirD2 activity. Aspartic acid at position 130, could be substituted with glutamic acid and to a much lesser extent, with tyrosine. In contrast, another conserved residue, asparagine 139, tolerated many different amino acid substitutions. The non-conserved residues, arginine 129, proline 132 and leucine 134, were also found to be important for function. Isolation of null mutations that map throughout this conserved domain confirm the hypothesis that this region is essential for function.

Molecular characterization of the melanocyte lineage-specific antigen gp100.

The glycoproteins recognized by monoclonal antibody (mAb) NKI-beteb are among the best diagnostic markers for human melanoma because their expression is restricted to melanocytic cells. Recently, we isolated a cDNA clone, termed gp100-c1, which confers immunoreactivity not only to mAb NKI-beteb, but also to two other mAbs used to diagnose malignant melanoma, HMB-50 and HMB-45. In this report, we demonstrate that gp100-c1 cDNA encodes glycoproteins of 100 kDa (gp100) and 10 kDa (gp10) which are recognized by these mAbs in human melanoma cells. The translation product deduced from the open reading frame present in gp100-c1 cDNA is highly homologous to another melanocyte-specific protein, Pmel17. Nucleotide sequence analysis of genomic DNA indicates that the transcripts corresponding to gp100 and Pmel17 cDNAs originate from a single gene via alternative splicing. In all normal and malignant melanocytic cells analyzed, gp100 and Pmel17 RNAs are simultaneously expressed.

Mutational analysis of Agrobacterium tumefaciens pTiA6 virD1: identification of functionally important residues.

Mutagenesis experiments were used to identify functionally important regions of Agrobacterium tumefaciens pTiA6 VirD1. Random mutations were introduced by using Taq polymerase in a mutagenic reaction buffer containing manganese and altered nucleotide ratios to increase errors during the polymerase chain reaction (PCR). The mutants were assayed for VirD1-, VirD2-dependent border-nicking activity in Escherichia coli harbouring a border-containing substrate plasmid. Analysis of the mutants led to the identification of a region from amino acids 45-60 that is important for VirD1 activity. This region corresponds to a previously postulated potential DNA-binding domain. Deletion mutagenesis indicated that amino acids 2-16 could be deleted without affecting VirD1 function, whereas a larger deletion, amino acids 5-27, completely inactivated VirD1.

Melanocyte lineage-specific antigens recognized by monoclonal antibodies NKI-beteb, HMB-50, and HMB-45 are encoded by a single cDNA.

The glycoproteins recognized by monoclonal antibody (MAb) NKI-beteb are among the best diagnostic markers for human melanoma. MAb NKI-beteb reacts with melanoma cells throughout tumor development and does not cross-react with other tumor or normal cells, except for cells of the melanocytic lineage. Two other melanocyte lineage-specific MAbs, HMB-50 and HMB-45, show a specificity and staining pattern strikingly similar to the ones observed for NKI-beteb. Herein, we demonstrate that all three MAbs recognize protein products encoded by a single cDNA. Expression of this cDNA in BLM cells results in immunoreactivity with all three MAbs. In addition, we demonstrate co-distribution of the RNA species detected by the cDNA with the proteins recognized by the MAbs in tissue sections.