Randomised controlled trial comparing an acute paediatric hospital at home scheme with conventional hospital care.

AIMS: To assess the clinical effectiveness of a paediatric hospital at home service compared to conventional hospital care. METHODS: A total of 399 children suffering from breathing difficulty (n = 202), diarrhoea and vomiting (n = 125), or fever (n = 72) were randomised to Hospital at Home or in-patient paediatric care. Main outcome measures were: comparative clinical effectiveness as measured by readmission rate within three months (used as a proxy for parental coping with illness); and length of stay/care and comparative satisfaction of both patients and carers. RESULTS: Clinical effectiveness of both services was not significantly different. Length of care was one day longer in the Hospital at Home group; however, most parents and children preferred home care. CONCLUSIONS: Hospital at Home is a clinically acceptable form of care for these groups of acute paediatric illness. Readmission rates within three months failed to show any advantage in terms of parental coping. Parents and patients expressed a strong preference for hospital at home.

Users' views on hospital and home care for acute illness in childhood.

This mainly qualitative study compared 40 families' experience of hospital and home care. This is one aspect of a randomised, controlled trial, which aimed to evaluate the clinical and cost effectiveness of a paediatric hospital at home service (HAH) for acute illness in children. This paper builds upon previous work that has aimed to examine parents' and children's views as service users. Forty families from a larger sample population took part in structured interviews. Eleven children aged 5 to 12 years took part in semistructured interviews. A drawing technique was the chosen method of augmentation in the children's interviews. Research findings showed that HAH is an acceptable alternative to hospital care where there are essentially nursing needs. Thirty-six (90%) parents and seven children stated a clear preference for HAH. The parents' preference was based on a perception that their child's illness wasn't serious or life threatening and therefore could be managed at home with appropriate support from health professionals. The social and financial costs of hospital care compared with HAH were the other main drivers, rather than a comparison of the quality of nursing care of their child.

Predictive genetic testing in maturity-onset diabetes of the young (MODY).

INTRODUCTION: Maturity-onset diabetes of the young (MODY) is characterized by autosomal dominant inheritance of young-onset non-insulin-dependent diabetes. It accounts for approximately 1% of Type 2 diabetes (approximately 20 000 people in the UK). Diagnostic and predictive genetic tests are now possible for 80% of MODY families. Diagnostic tests can be helpful as the diagnosis can be confirmed and the subtype defined which has implications for treatment and prognosis. However predictive genetic testing, particularly in children, raises many scientific, ethical and practical questions. METHODS: This is a case report of a family with diabetes resulting from an hepatic nuclear factor (HNF)1alpha mutation, who request a predictive test in their 5-year-old daughter. The scientific issues arising from molecular genetic testing in MODY are discussed, along with the process of genetic counselling. The views of the family and the clinical genetics team involved are presented. RESULTS: The implications of positive and negative predictive test results and the possibility of postponing the test were among many issues discussed during genetic counselling. The family remained convinced the test was appropriate for their daughter and the clinical genetics team fully supported this decision. The family, motivated by their family history of diabetes and personal experiences of the disease, wished to reduce uncertainty about their daughter's future irrespective of the result. CONCLUSIONS: This case emphasizes that decisions on predictive testing are very personal and require appropriate counselling.

Organic ion imaging of biological tissue with secondary ion mass spectrometry and matrix-assisted laser desorption/ionization.

Organic secondary ion mass spectrometry (SIMS) and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry can be used to produce molecular images of samples. This is achieved through ionization from a clearly identified point on a flat sample, and performing a raster of the sample by moving the point of ionization over the sample surface. The unique analytical capabilities of mass spectrometry for mapping a variety of biological samples at the tissue level are discussed. SIMS provides information on the spatial distribution of the elements and low molecular mass compounds as well as molecular structures on these compounds, while MALDI yields spatial information about higher molecular mass compounds, including their distributions in tissues at very low levels, as well as information on the molecular structures of these compounds. Application of these methods to analytical problems requires appropriate instrumentation, sample preparation methodology, and a data presentation usually in a three-coordinate plot where x and y are physical dimensions of the sample and z is the signal amplitude. The use of imaging mass spectrometry is illustrated with several biological systems.

Secondary ion images of the rodent brain.

Sections of biologic tissue obtained from laboratory rodents are prepared and analyzed by secondary ion mass spectrometry. The intensity of phosphocholine secondary ions is used to identify anatomical features of the brain from secondary ion images and to evaluate the effectiveness of procedures developed. Secondary ion emission of phosphocholine (m/z 184), is found to be abundant and its intensity is heterogeneous. Effects of sample thickness are addressed. Correspondence between conventional optical images of stained tissue and secondary ion images shows that successive ion images may be used to produce a three-dimensional map of the brain, i.e., an atlas.

Identification and mapping of phosphocholine in animal tissue by static secondary ion mass spectrometry and tandem mass spectrometry.

Secondary ion mass spectra and images were obtained from animal tissue samples using less than 10(13) primary ions/cm2. The mass spectra showed abundant peaks at m/z 184 and m/z 86. Tandem mass spectrometry (MS/MS) was used to identify the source of these ions as phosphocholine. Secondary ion images obtained using MS/MS were used to show that m/z 86 is an abundant gas-phase fragment ion derived from m/z 184. These results are discussed in terms of the physiology of the samples investigated.

Massive cluster ablation as preparation for organic secondary ion imaging.

A focused Cs+ beam was used to obtain secondary ion mass spectra and images from samples of stearic acid on gold before and after ablation by a beam of massive cluster ions. Ablation appears to have two effects on secondary ion emission. First, the number and intensity of peaks reflecting contamination are substantially reduced. Secondly, the absolute intensity of secondary ion current characteristic of the analyte increases. These features simplify mass spectra and improve contrast in the images obtained.

Organic ion imaging beyond the limit of static secondary ion mass spectrometry.

Secondary ion mass spectra and images were obtained from spikes of choline chloride, acetylcholine chloride, and methylphenylpyridinium iodide deposited onto specimens of porcine brain tissue. Samples were subsequently subjected to a dose of 10-keV Cs(+) sufficient to suppress secondary ion emission characteristic of the targeted analytes. Following ablation of the samples by massive glycerol clusters generated by electrohydrodynamic emission, secondary ion mass spectra and images could be obtained that reflected the identity and location of the spiked analytes. The absolute intensity of secondary ion emission that followed ablation was found to be between 30 and 100% of the intensity obtained prior to exposure to the high dose of Cs'. Not all chemical noise is removed by ablation, however, so that the signal-to-noise ratios after ablation correspond to between 10 and 85% of their values observed under conditions of low primary ion dose.

Recurrence of Pallister-Hall syndrome in two sibs.

We report the first definite sib recurrence of Pallister-Hall syndrome in a family without a cytogenetically visible chromosome abnormality. The father of these two sibs was born with nearly identical digital abnormalities and could represent either mild expression or gonosomal mosaicism for a dominant gene.

Improved energy compensation for time-of-flight mass spectrometry.

A model for improved energy compensation in time-of-flight (TOF) mass spectrometry has been developed and tested. This model includes effects of both the acceleration and drift region on mass resolution for surface desorption TOP mass spectrometers that employ ion mirrors to improve mass resolution. Appropriate placement of an additional stage onto the conventional one- and two-stage mirrors provides compensation for flight time spreads, caused by initial ion kinetic energy distributions, in both regions. Experimental results that validate the model calculations are presented for a modified commercial two-stage ion mirror. For example, m/†m for Na(+) was improved from ∼ 100 to ∼ 200 using only a 200-eV drift energy and a 58-cm drift path.

Charge compensation for imaging large insulating samples by using secondary ion tandem mass spectrometry.

A charge compensation technique has been developed for secondary ion mass spectrometry and imaging of insulating samples as large as 1 cm(2) using a triple quadrupole-based microprobe. The microprobe secondary ion extraction field is synchronized with a periodic primary Cs(+) beam to allow a sheetlike beam of 5-eV electrons to pass over the sample surface when the extraction field is zeroed. Electrons are attracted to, and neutralize, any points on the sample that have accumulated positive charge. Positive secondary ion images from Teflon®, a well-known insulator, illustrate the effectiveness of charge compensation. Locating and identifying analytes on dry filter paper by using tandem mass spectrometry are also demonstrated.

Secondary ion emission from solutions: time dependence and surface phenomena.

The temporal behavior of FAB mass spectra from glycerol solutions of tetradecyltrimethylammonium bromide (C14H29-N(CH3)3Br, TTAB) and tetraethylammonium iodide (TEAI) was investigated. FAB spectra of the TTAB solution displayed a continuous decrease in TTA+ with time. Spectra obtained from the TEAI solution were initially invariant for several minutes and then displayed a gradual increase in the relative abundance of TEA+ to a maximum, followed by a precipitous drop in ion intensity. Secondary ion images of droplets of TTAB solution showed that emission of both TTA+ and glycerol secondary ions was homogeneous across the sample. Secondary ion images of droplets of TEAI solution showed heterogeneous and segregated emission of both TEA+ and protonated glycerol. Results from the FAB spectra and the secondary ion images were correlated and rationalized on the basis of surface tension-induced mass transport and matrix evaporation.

Organic ion imaging using tandem mass spectrometry.

A triple-quadrupole mass spectrometer has been interfaced with a wide-angle secondary ion microprobe. The combination permits acquisition of data necessary to determine the distribution of targeted organic analytes even in the presence of overwhelming isobaric interference. Micrographs generated from secondary ion intensity alone are compared to those generated using secondary ionization with tandem mass spectrometry (MS/MS), both for image reference and to show the improvement in image quality that can be attained when MS/MS is employed. Inhomogeneous mixtures of glycerol, KCl, and asparagine on 1-cm-diameter aluminum targets were used to demonstrate the instrument's selectivity. Secondary ions generated from samples of this system include isobaric 133Cs+ implanted from the primary ion beam, the 41K(+)-glycerol adduct, and protonated asparagine.

Solution chemistry and secondary ion emission from amine-glycerol solutions.

Analytical Chemistry Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA Secondary ion mass spectra were obtained from a series of C4-C10 n-alkylamines introduced via the gas phase onto glycerol. It was found that the amine-characteristic secondary ion intensity varied linearly with amine partial pressure. Henry's law constants and surface activity constants for each of the amines in glycerol solution were measured. A linear correlation was found between amine-characteristic secondary ion intensity and Henry's law concentrations. The concentrations calculated from Henry's law were too low to yield the intensities observed, indicating that secondary ion precursors were not free-base amine molecules but ions in solution. Explicit kinetic equations describing glycerol and amine protonation and deprotonation as a result of primary ion damage to the solutions are derived to rationalize the observed spectra.

Monitor for displaying real-time images of low energy ion beams.

Analytical Chemistry Division. Oak Ridge National Laboratory. Oak Ridge, Tennessee, USA A monitor that provides real-time images of low energy (< 50 eV) ion beams has been designed, constructed, and tested. The cross-sectional image of the beam at the entrance aperture of the monitor is magnified by a factor of 6.5 and displayed on a CRT, following current amplification by using a dual microchannel plate assembly. The monitor provides unambiguous information regarding the cross section of any low energy ion beam. Anplication in the design and testing of quadrupole-based mass spectrometers is emphasized.

A wide-angle secondary ion probe for organic ion imaging.

A secondary ion source has been developed for an organic ion microprobe capable of imaging samples up to 2 em in diameter. The source uses a focused 5 keY Cs(+) ion beam which is rastered across the sample surface, and secondary ions from each point on the sample are collected and formed into a low energy beam to be analyzed by a quadrupole mass filter. Dynamic emittance matching is employed to deflect ions from off-axis points on the sample back onto the mass analyzer axis. Rastering and dynamic emittance matching are rapidly controlled by assembly language programs using an IBM/AT (80286) type computer. A low energy ion monitor was used to tune and evaluate the secondary ion source by providing a magnified cross-sectional image of the ion beam at the source exit aperture. A well-focused and centered secondary ion beam was obtained from each point on the sample, indicating that large-scale dynamic emittance matching with high collection efficiency is possible. Mass resolved images of grids and glycerol samples are shown to demonstrate the performance of the integrated secondary ion source mass analyzer and control system.

Inguinal hernias are common in preterm infants.

The incidence of inguinal hernia was compared in term and preterm infants. The risk was considerably higher in the preterm group in both sexes. No particular complications of preterm birth were found to predispose to inguinal hernia.

Late effects on the left upper limb of subclavian flap aortoplasty.

The subclavian flap aortoplasty gives excellent short-term and medium-term results when performed on infants with coarctation of the aorta. This study was devised to determine whether there were any detrimental effects to the sacrifice of the left subclavian artery in infancy. Sixteen patients were studied 2 to 9 years post-operatively. Clinical evaluation revealed no major symptoms in the left upper limb. However, in seven children, minor symptoms had been noted by the parents. Anthropometric measurements revealed a shortening of the left upper limb in all patients; when these measurements were compared with those in normal subjects, the shortening was localized to the left upper arm. Four papers which mention the effect on the left arm of ligation of the subclavian artery in childhood during the Blalock-Taussig operation are discussed. It is concluded that the excellent results from the subclavian flap aortoplasty are not compromised by the minor effects of ligating the left subclavian artery in infancy.