Rationally subdividing the fly nervous system with versatile expression reagents.

The ability to image and manipulate specific cell populations in Drosophila enables the investigation of how neural circuits develop and coordinate appropriate motor behaviors. Gal4 lines give genetic access to many types of neurons, but the expression patterns of these reagents are often complex. Here, we present the generation and expression patterns of LexA lines based on the vesicular neurotransmitter transporters and Hox transcription factors. Intersections between these LexA lines and existing Gal4 collections provide a strategy for rationally subdividing complex expression patterns based on neurotransmitter or segmental identity.

An audit of the management of heart murmurs on the postnatal wards.

BACKGROUND: Investigation and management of neonatal heart murmurs varies widely and is dependent on local resources. In order to standardise the management of heart murmurs in our hospital a guideline (based on clinical examination with selective cardiology review) was introduced. AIMS: To establish adherence to and safety of the guideline; to review workload implications and to define the causes of neonatal heart murmurs in our population. METHODS: Patients were prospectively identified over a 2-year period (August 2006 to July 2008). Case notes were reviewed and examination findings, investigations, follow up and diagnosis recorded. RESULTS: 89 babies were identified. The guideline was generally well adhered to. In total 51 (57%) of babies were referred for cardiology assessment. In 40 babies this assessment included an echocardiogram. 30 babies (34%) had an underlying cardiac malformation: 25 were identified before discharge home. 15/30 (50%) of the babies with a cardiac malformation remain under cardiology follow up at the age of 1 year. No baby discharged from follow up without cardiology review subsequently presented with a cardiac problem. CONCLUSION: A significant minority of babies with a heart murmur have an underlying cardiac malformation. Our guideline appears to ensure the timely identification of these babies and rationalises our use of specialist services.

Impact and workload implications on service provision with establishment of a neonatal complex airway service in Scotland.

The objective of this study was to assess if any changes have occurred in the utilization of neonatal services with referral for neonatal airway assessment and how this is related to the establishment of a National Complex Airway Service. A retrospective case-note review was performed for neonates referred for airway assessment from 2004-2010 inclusive. Seventy-nine neonates were referred from throughout Scotland; 10 in 2004-2006, 24 in 2007-2008 and 45 in 2009-2010. The mean gestational age was 35 weeks; 39% were preterm. Stridor was the most common reason for referral (46%). The most common diagnosis was airway malacia (38%). Fifty-three procedures were performed on the ward. In total, 64 microlaryngobronchoscopies were performed; 45 diagnostic and 19 interventional. The most common intervention was supraglottoplasty for airway malacia. Thirty-five separate airway procedures were undertaken. Additional investigations were frequently requested and co-morbidities were common. Since the establishment of the Scottish National Complex Airway Service in 2006, referrals for neonatal airway assessment have increased significantly. The reasons for this include a greater awareness of the service, improved treatment options and increased preterm survival. These neonates frequently have associated co-morbidities and require a repertoire of specialist input. This increase has significant implications for further service provision.

Rationalized assessment of prolonged jaundice is safe and cost-effective.

Prolonged jaundice (PJ) in healthy term neonates is common and frequently benign. It can, however, be the earliest manifestation of underlying liver disease. Its management requires a balanced approach, avoiding over-investigation of well babies while ensuring the early identification of those with pathology. Currently marked heterogeneity exists in the assessment of PJ. Over a two-year period we prospectively audited the management of PJ in two Level 3 neonatal units prior to and after the introduction of a rationalized investigation algorithm in keeping with the recently published British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN) guidelines (i.e. clinical examination and stool inspection combined with measurement of split bilirubin). In this study we reviewed initial practice and then evaluated the impact of our change in practice. A total of 197 babies, 1.5% of live births, were referred with PJ. Of these, 105 babies were included in the first part of the study and 92 babies were included in the second part. No pathology relating to PJ, such as infection, hepatitis or liver disease, was identified. Following the introduction of our rationalized algorithm, we demonstrated a statistically significant reduction in the number of return appointments (28 versus 7; P < 0.0009) and repeat investigations (37 versus 7; P < 0.0001). This represented a saving of £1575-2625 per year in laboratory costs alone. Contemporaneously, three infants presented with biliary atresia, none of whom were identified by PJ screening and all of whom were over seven weeks old at diagnosis. A rationalized approach to the assessment of PJ reduces workload and is cost-effective; however, the limitations of selective screening, irrespective of how streamlined it is, remain--if babies are not identified and referred, they cannot be screened. Population-based methodologies offer an alternative approach to the identification of cholestatic liver disease and are worthy of further consideration.

Switching repulsion to attraction: changing responses to slit during transition in mesoderm migration.

Slit is secreted by cells at the midline of the central nervous system, where it binds to Roundabout (Robo) receptors and functions as a potent repellent. We found that migrating mesodermal cells in vivo respond to Slit as both an attractant and a repellent and that Robo receptors are required for both functions. Mesoderm cells expressing Robo receptors initially migrate away from Slit at the midline. A few hours after migration, these same cells change their behavior and require Robo to extend toward Slit-expressing muscle attachment sites. Thus, Slit functions as a chemoattractant to provide specificity for muscle patterning.

Short-range and long-range guidance by slit and its Robo receptors. Robo and Robo2 play distinct roles in midline guidance.

Previous studies showed that Roundabout (Robo) in Drosophila is a repulsive axon guidance receptor that binds to Slit, a repellent secreted by midline glia. In robo mutants, growth cones cross and recross the midline, while, in slit mutants, growth cones enter the midline but fail to leave it. This difference suggests that Slit must have more than one receptor controlling midline guidance. In the absence of Robo, some other Slit receptor ensures that growth cones do not stay at the midline, even though they cross and recross it. Here we show that the Drosophila genome encodes three Robo receptors and that Robo and Robo2 have distinct functions, which together control repulsive axon guidance at the midline. The robo,robo2 double mutant is largely identical to slit.

An unusual cause of neonatal coagulopathy and liver disease.

Congenital thyrotoxicosis is a rare and potentially fatal illness. We report a case in a preterm infant delivered to a mother known to have autoimmune endocrine disease. Diagnosis was difficult because the infant's presenting symptoms and signs closely resembled congenital viral infection with co-existent hepatic dysfunction and coagulopathy. The associated hepatic dysfunction was so severe that liver biopsy was scheduled before the diagnosis emerged. A high degree of clinical suspicion coupled with prenatal identification of pregnancies at risk of complication by congenital thyrotoxicosis is imperative to facilitate prompt diagnosis and treatment.

Virologic responses to a ritonavir--saquinavir-containing regimen in patients who had previously failed nelfinavir.

OBJECTIVES: The effectiveness of a second protease inhibitor in patients who failed an initial protease inhibitor is unclear but believed to be low. It has been postulated, however, that patients who fail nelfinavir may respond differently. We therefore assessed the virologic response to a ritonavir-saquinavir-containing regimen in patients who had previously failed nelfinavir. METHODS: A total of 26 patients enrolled in the nelfinavir clinical trials AG506 and AG511 at our two sites who failed (two consecutive HIV viral loads > 5000 copies/ml; branched DNA assay) were switched to a combination of stavudine 40 mg twice daily, lamivudine 150 mg twice daily, ritonavir 400 mg twice daily and saquinavir 400 mg twice daily. RESULTS: The mean viral load at enrollment in this study was 46 674 copies/ml (range, 1075-146400 copies/ml). The median CD4 cell count was 222 x 10(6)/l (range, 82-448 x 10(6)/l). The median duration of nelfinavir use with a detectable viral load before the switch occurred was 48 weeks. Two patients discontinued the study at 3 weeks. All of the remaining patients (n = 24) reached undetectable viral loads (< 500 copies/ml) that were sustained at week 24 in 17 (71%) out of 24 subjects. The most frequent baseline mutations in the protease gene prior to switching were D30N (13 out of 18), N88D (eight out of 18) and M36I (eight out of 18). The presence or absence of these mutations was not predictive of a short-term virologic response. CONCLUSIONS: Most patients who failed a nelfinavir-containing regimen responded to a switch to a combination regimen with saquinavir-ritonavir.

Morphine, experimental pain, and psychological reactions.

This study examines the effects of morphine (10 mg/70 kg body weight) versus placebo (isotonic saline) on experimentally induced cold pressor pain threshold and tolerance, on self-reports of psychological states and drug effects, observer ratings of psychological states, and performance on timed cognitive-motor tasks in 20 non-drug using, normal male volunteers (21-28 years of age). Morphine increased both threshold and tolerance for cold pressor pain, and also increased "euphoric" and decreased "clear thinking" responses on the respective scales. Morphine, in contrast to placebo, increased scores on depression, fatigue, and cognitive loss-dysfunction scales and decreased scores on carefree and "friendliness" scales. Three sets of psychological variables were observed to covary significantly: Measures of anxiety and hostility; reports of fatigue and cognitive dysfunction; and reports of carefree feelings and perceptions of clear thinking. While measures of hostility, fatigue, and cognitive dysfunction covaried positively, reports of carefree feelings and perception of clear thinking covaried negatively with increased pain threshold and tolerance. Anxiety, contrary to reports in the literature, also covaried positively with the pain measures. The results were interpreted as supporting a relationship between increased arousal of the nervous system and decreased pain sensitivity in conjunction with the known analgesic effects of morphine.

1H and 31P NMR study of speciation in systems containing ADP, Al3+, and fluoride.

It has been proposed that AlF4- can serve as a tetrahedral pseudophosphate bound to guanosine diphosphate (GDP) [or other nucleoside diphosphates (NDP)] in G-protein systems. In a previous paper [D. J. Nelson and R. B. Martin, J. Inorg. Biochem. 43, 37 (1991)], 19F and 1H NMR were used to analyze the ternary system Al(3+)-NDP-F- in aqueous solutions. Ternary complexes (NDP)AlFx (with x = 1-3) were identified, but no (NDP)AlF4 was found. In this paper, the equilibrium constants for ternary complex formation that were obtained in the previous paper were further tested in a more extensive 1H and 31P NMR study of speciation in systems that contained Al3+, F-, and adenosine 5'-diphosphate (ADP). The results of the study are in general support of previously derived constants for ternary complexes and also provide support for the existence at relatively high ADP concentration (approximately 10 mM) of a base-stacked intermolecular dihydroxy-di-Al3+ bridged ADP dimeric structure at an ADP to Al3+ molar ratio of 1:1. 31P NMR of the dimer reveals that each of the two Al3+ ions is bidentately coordinated to the alpha and beta phosphates of a single (but different) ADP molecule. Evidence is also presented for the existence at relatively low ADP concentration (approximately 0.5 mM) of a monomeric species in which a single Al3+ ion is coordinated to alpha and beta phosphates of a single ADP molecule. 1H NMR of the monomeric species reveals the expected "wrong-way chemical shift" of the adenine C8 proton upon Al3+ ion complexation to the phosphate chain.

Reducing medication errors in the neonatal intensive care unit.

BACKGROUND: Medication errors are common in the neonatal intensive care unit (NICU). Various strategies to reduce errors have been described in adult and paediatric patients but there are few published data on their effect in the NICU. AIM: To describe the medication errors occurring within an NICU, and assess the impact of a combined risk management/clinical pharmacist led education programme on these errors. METHODS: Medication errors were identified prospectively over one year by critical incident reporting. Four months into the study, a pharmacist led education programme was instituted. This involved a daily, cot side, pharmacist led review of medication orders. Each new member of pharmacy, nursing, or medical staff was also required to successfully complete a series of dose calculations. In addition, a risk management approach was used to make several changes in practice during the study period. RESULTS: A total of 105 errors were identified, four serious, 45 potentially serious, and 56 minor. The four serious errors included two tenfold dose miscalculations. Most (71%) of the errors were due to poor prescribing. After the introduction of our interventions, monthly medication errors fell from a mean (SD) of 24.1 (1.7) per 1000 neonatal activity days to 5.1 (3.6) per 1000 days (p < 0.001) in the following three months. The subsequent change over of junior medical staff was associated with a significant increase in medication errors to 12.2 (3.6) per 1000 neonatal activity days (p = 0.037). However, the number remained significantly less than before our interventions (p < 0.001). Three serious errors occurred in the first four months compared with one in the second eight month period, the latter corresponding to the six monthly change over of junior medical staff. CONCLUSIONS: Medication errors are common in NICUs. Fortunately, actual harm to an infant is rare. Interventions to reduce errors, particularly within the context of a risk management programme, are effective.

Paediatric sedation for CT scanning: the safety and efficacy of quinalbarbitone in a district general hospital setting.

The aim of this study was to review retrospectively the safety and efficacy of a paediatric sedation protocol in a district general hospital radiology department. 256 children attended for CT scanning over a 40-month period. 40 children required sedation and were given quinalbarbitone. 34 (85%) of this group were adequately sedated. Of the children who received quinalbarbitone, 35 were under 5 years of age. 32 of this group (91.4%) were adequately sedated. Failures in children under 5 years were all caused by problems with administration whilst failures in the older children were due to paradoxical excitement. No problems with respiratory depression were encountered. Sedation can be safely performed in a district general hospital radiology department if a structured protocol is adhered to. Quinalbarbitone is a safe, effective oral agent in children under the age of 5 years.

Short-term outcomes following intrauterine transfusion in Scotland.

AIM: To describe neonatal outcomes following intrauterine transfusion (IUT) for severe Rhesus isoimmunisation from 1993 to 2004. RESULTS: 116 neonates who had undergone 457 IUTs (median 4, range 1-9) were identified. Three neonates died, all before 1995 (two because of hypoxic ischaemic multiorgan failure and one because of overwhelming Escherichia coli sepsis). 13 neonates (11%) were delivered by emergency Caesarean section following either IUT complication or spontaneous onset of preterm labour. They were more likely to require intubation (p<0.0001), on-going respiratory support (p=0.0007) and an exchange transfusion (p=0.007). 23 (20%) required an exchange transfusion and 63 (54%) at least one top-up transfusion. CONCLUSIONS: Management of severe Rhesus disease is associated with encouraging neonatal outcomes and most infants can be managed with phototherapy and a few top-up transfusions. IUT complications are rare but significantly increase neonatal mortality and morbidity. Antenatal counselling should address the likely postnatal course for these infants.

Short-range and long-range guidance by Slit and its Robo receptors: a combinatorial code of Robo receptors controls lateral position.

Slit is secreted by midline glia in Drosophila and functions as a short-range repellent to control midline crossing. Although most Slit stays near the midline, some diffuses laterally, functioning as a long-range chemorepellent. Here we show that a combinatorial code of Robo receptors controls lateral position in the CNS by responding to this presumptive Slit gradient. Medial axons express only Robo, intermediate axons express Robo3 and Robo, while lateral axons express Robo2, Robo3, and Robo. Removal of robo2 or robo3 causes lateral axons to extend medially; ectopic expression of Robo2 or Robo3 on medial axons drives them laterally. Precise topography of longitudinal pathways appears to be controlled by a combination of long-range guidance (the Robo code determining region) and short-range guidance (discrete local cues determining specific location within a region).