Dwell time and risk of central-line-associated bloodstream infection in neonates.

BACKGROUND: Umbilical venous catheters (UVCs) or peripherally inserted central catheters (PICCs), widely used in high-risk neonates, may have a threshold dwell time for subsequent increased risk of central-line-associated bloodstream infection (CLABSI). AIM: To evaluate the CLABSI risks in neonates having either UVC, PICC, or those having both sequentially. METHODS: The study included 3985 infants who had UVC or PICC inserted between 2007 and 2009 cared for in 10 regional neonatal intensive care units: 1392 having UVC only (group 1), 1317 PICC only (group 2), and 1276 both UVC and PICC (group 3). FINDINGS: There were 403 CLABSIs among 6000 venous catheters inserted, totalling 43,302 catheter-days. CLABSI rates were higher in group 3 infants who were of lowest gestation (16.9 per 1000 UVC-days and 12.5 per 1000 PICC-days; median: 28 weeks) when compared with group 1 (3.3 per 1000 UVC-days; 37 weeks) and group 2 (4.8 per 1000 PICC-days; 30 weeks). Life table and Kaplan-Meier hazard analysis showed that UVC CLABSI rate increased stepwise to 42 per 1000 UVC-days by day 10, with the highest rate in group 3 (85 per 1000 UVC-days). PICC CLABSI rates remained relatively stable at 12-20 per 1000 PICC-days. Compared to PICC, UVC had a higher adjusted CLABSI risk controlled for dwell time. Among group 3, replacing UVC electively before day 4 may have a trend of lower CLABSI risk than late replacement. CONCLUSION: There was no cut-off duration beyond which PICC should be removed electively. Early UVC removal and replacement by PICC before day 4 might be considered.

Bone marrow-derived cells as progenitors of lung alveolar epithelium.

We assessed the capacity of plastic-adherent cultured bone marrow cells to serve as precursors of differentiated parenchymal cells of the lung. By intravenously delivering lacZ-labeled cells into wild-type recipient mice after bleomycin-induced lung injury, we detected marrow-derived cells engrafted in recipient lung parenchyma as cells with the morphological and molecular phenotype of type I pneumocytes of the alveolar epithelium. At no time after marrow cell injection, did we detect any engraftment as type II pneumocytes. In addition, we found that cultured and fresh aspirates of bone marrow cells can express the type I pneumocyte markers, T1alpha and aquaporin-5. These observations challenge the current belief that adult alveolar type I epithelial cells invariably arise from local precursor cells and raise the possibility of using injected marrow-derived cells for therapy of lung diseases characterized by extensive alveolar damage.

Use of benzo[a]pyrene relative abundance ratios to assess exposure to polycyclic aromatic hydrocarbons in the ambient atmosphere in the vicinity of a Söderberg aluminum smelter.

The purpose of this study was to investigate the use of benzo[a]pyrene (B[a]P) relative abundance ratios (RARs) to assess exposure to polycyclic aromatic hydrocarbons (PAHs) in the urban atmospheric air in the vicinity of a horizontal stud Söderberg aluminum reduction facility. The B[a]P RARs refer to the concentration of individual PAHs measured in a given sample divided by the concentration of B[a]P found in the same sample. This study compared the B[a]P RARs calculated for the facility stack and three sites near the Söderberg aluminum smelter for three different sampling periods. Interperiod differences were significant for many of the PAHs, and the differences between the stations proved insignificant at p < 0.05. The differences between each individual station and the facility stack were significant for all PAHs. B[a]P RARs increased in value at the stations compared with the stack, indicating that B[a]P may be degraded or removed from the atmosphere at a rate greater than that of the majority of the measured PAHs. It is concluded that B[a]P and B[a]P RARs may be poor markers of exposure to PAHs in the vicinity of this Söderberg aluminum refinery for the entire mixture of PAHs present in the ambient atmosphere.

Incidence of childhood-onset Type 1 diabetes mellitus in Devon and Cornwall, England, 1975-1996.

AIMS: To determine the incidence of Type 1 diabetes mellitus (DM) in children aged 0-15 years in the far south-west of England between 1975 and 1996. METHODS: Patient information was collected to set up the Cornwall and Plymouth Children's Diabetes Register (CPCDR) through two main data sources; hospitals and the general practitioners in all surgeries in the study region. All children under 16 years living within Cornwall and the Isles of Scilly, and the former Plymouth Health Authorities and diagnosed as having Type 1 DM during the study period were included. The case ascertainment was estimated by a capture-recapture method. Trends and differences in incidence of sex, age, time period and district of diagnosis were analysed by Poisson regression analysis. Roger's method was used to estimate the seasonal variations. RESULTS: A total of 522 subjects aged between 0 and 15 years were identified from 01/01/1975 to 31/12/1996, giving an overall crude incidence of 14.9/ 100 000 population/year. The case ascertainment was 94.4% (95% confidence interval (CI) 91.4- 97.6%) for the whole register. Poisson regression analysis showed that a significant increase of incidence (2.49% per year) was observed throughout the 22-year study period, which was mainly a result of the significant increase in the 0-4 year age-group (6.29% per year). The incidence significantly differed among the 22-years (P = 0.007), the three age groups (0-4, 5-9 and 10-14 years, P<0.001) and different sexes (P=0.049). The significant seasonal variations were detected with peak incidence appearing in autumn and winter. CONCLUSIONS: The first validated childhood-onset diabetes register has been set up in the far south-west of England. The incidence of childhood Type 1 DM in this region has increased significantly over the past two decades, especially in children under 5 years.

How postnatal support groups can benefit new parents.

This paper highlights the need for support for new mothers and explains how health visitors researched the need for, and set up, a postnatal support group.

Health visitors' perceptions of breastfeeding mothers.

A study to assess health visitors' perceptions of pregnant women most likely to breastfeed revealed that many did not recognise the significance of all factors identified in previous research as indicating a negative attitude. CHRISTOPHER DRACUP and ELIZABETH SANDERSON discuss the application of these factors in identifying mothers for breastfeeding promotion.

Upregulation of nicotinic receptors following continuous infusion of nicotine is brain-region-specific.

Rats receiving 4 mg nicotine/kg/day via implanted minipumps sustained plasma nicotine concentrations of 40 ng/ml throughout two weeks of nicotine infusion. Numbers of brain [3H]nicotine binding sites were increased by about 50% in cortex and hippocampus whereas numbers of [3H]nicotine binding sites in striatum were unaffected by nicotine treatment at either of the timepoints examined (7, 14 days). Cortical [125I] alpha-bungarotoxin and [3H]QNB binding sites were also unchanged. The regional selectivity of nicotinic receptor modulation may reflect the low dose of nicotine used and the mode of administration. The changes observed may be pertinent to the continuous administration of nicotine in man, via transdermal nicotine patches.

Presynaptic nicotinic receptors and the modulation of transmitter release.

Nicotine is increasingly recognized to promote transmitter release in the brain by a direct action on presynaptic terminals. Pharmacological evidence indicates that this action is mediated by nicotinic receptors. From their sensitivity to mecamylamine, neosurugatoxin and neuronal bungarotoxin these presynaptic receptors can be distinguished from alpha-bungarotoxin-sensitive muscle-type nicotinic receptors, and can be correlated with [3H] nicotine binding sites in the brain. The release of many transmitters in different brain regions is susceptible to stimulation by nicotine, but this effect is not ubiquitous. However, lesioning and subcellular fractionation studies suggest that the majority of brain nicotine receptors are located presynaptically, so that a direct influence of nicotine on transmitter release assumes considerable importance. Although the sensitivity of presynaptic receptors is such that they are likely to be partially activated by doses of nicotine obtained by smoking, the desensitization-induced up-regulation of nicotinic binding sites that follows chronic nicotine treatment raises questions about their functional status during tobacco usage. Chronic administration of the agonist (+)anatoxin-a also up-regulated [3H] nicotine binding sites, and led to increased nicotine-evoked transmitter release in vitro. This could have implications for the involvement of these receptors during withdrawal.

Surgical treatment of constipation.

A 30-year retrospective review of 544,354 Seattle area hospital admissions yielded 25 patients who underwent surgical therapy for the relief of intractable idiopathic constipation. All patients were refractory to conventional medical treatment consisting of the daily use of laxatives, cathartics, emollients or enemas. Long-term follow-up was available for 13 of the 25 patients. All 13 patients had clinical improvement as a result of the operation. This confirms results reported by other authors. Subtotal colectomy and left hemicolectomy are the procedures generally favored.