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PURPOSE: To investigate the predictive validity for health decline of a standard of living, a measure that combines basic necessities and consumer durables.METHOD:A nationally representative sample of those aged 55-69 years was interviewed at home in the Great Britain Retirement and Retirement Plans Survey, (1988; n=3,541). In 1994, 2,247 were re-interviewed, response rate being 70% of survivors. Relationships between socioeconomic status and health decline were investigated using polytomous logistic regression modelling. The outcomes were onset of functional limitation and mortality.RESULTS:Standard of living was an independent predictor of 6-year functional limitation onset (Odds Ratio compared to good standard of living 2.2; 95% Confidence Interval 1.3-3.8) and mortality (OR=4.6; 95% CI 2.3-8.9) in women, with age, household type, educational qualifications and social class taken into account. However, in men, weaker associations were largely accounted for by differences in education and social class (adjusted OR for functional limitation onset 1.0; 95% CI 0.5-1.9; adjusted OR for mortality 1.4; 95% CI 0.6-2.9). A combined indicator of housing tenure and property value was also an independent predictor of functional limitation onset in women.CONCLUSIONS: Poor standard of living identifies women but not men at risk of health decline who are missed by social class and educational level. Measures of current home-based material resources are a useful addition to minimum datasets for monitoring health inequalities. [ABSTRACT FROM AUTHOR]

Abstract Background Food security is an issue that has come under renewed scrutiny amidst concerns that substantial yield increases in cereal crops are required to feed the world’s booming population. Wheat is of fundamental importance in this regard being one of the three most important crops for both human consumption and livestock feed; however, increase in crop yields have not kept pace with the demands of a growing world population. In order to address this issue, plant breeders require new molecular tools to help them identify genes for important agronomic traits that can be introduced into elite varieties. Studies of the genome using next-generation sequencing enable the identification of molecular markers such as single nucleotide polymorphisms that may be used by breeders to identify and follow genes when breeding new varieties. The development and application of next-generation sequencing technologies has made the characterisation of SNP markers in wheat relatively cheap and straightforward. There is a growing need for the widespread dissemination of this information to plant breeders. Description CerealsDB is an online resource containing a range of genomic datasets for wheat (Triticum aestivum) that will assist plant breeders and scientists to select the most appropriate markers for marker assisted selection. CerealsDB includes a database which currently contains in excess of 100,000 putative varietal SNPs, of which several thousand have been experimentally validated. In addition, CerealsDB contains databases for DArT markers and EST sequences, and links to a draft genome sequence for the wheat variety Chinese Spring. Conclusion CerealsDB is an open access website that is rapidly becoming an invaluable resource within the wheat research and plant breeding communities.

Abstract Background Multi-center magnetic resonance imaging (MRI) studies present an opportunity to advance research by pooling data. However, brain measurements derived from MR-images are susceptible to differences in MR-sequence parameters. It is therefore necessary to determine whether there is an interaction between the sequence parameters and the effect of interest, and to minimise any such interaction by careful choice of acquisition parameters. As an exemplar of the issues involved in multi-center studies, we present data from a study in which we aimed to optimize a set of volumetric MRI-protocols to define a protocol giving data that are consistent and reproducible across two centers and over time. Methods Optimization was achieved based on data quality and quantitative measures, in our case using FreeSurfer and Voxel Based Morphometry approaches. Our approach consisted of a series of five comparisons. Firstly, a single-center dataset was collected, using a range of candidate pulse-sequences and parameters chosen on the basis of previous literature. Based on initial results, a number of minor changes were implemented to optimize the pulse-sequences, and a second single-center dataset was collected. FreeSurfer data quality measures were compared between datasets in order to determine the best performing sequence(s), which were taken forward to the next stage of testing. We subsequently acquired short-term and long-term two-center reproducibility data, and quantitative measures were again assessed to determine the protocol with the highest reproducibility across centers. Effects of a scanner software and hardware upgrade on the reproducibility of the protocols at one of the centers were also evaluated. Results Assessing the quality measures from the first two datasets allowed us to define artefact-free protocols, all with high image quality as assessed by FreeSurfer. Comparing the quantitative test and retest measures, we found high within-center reproducibility for all protocols, but lower between-center reproducibility for some protocols than others. The upgrade showed no important effects. Conclusions We were able to determine (for the scanners used in this study) an optimised protocol, which gave the highest within- and between-center reproducibility of those assessed, and give details of this protocol here. More generally, we discuss some of the issues raised by multi-center studies and describe a methodical approach to take towards optimization and standardization, and recommend performing this kind of procedure to other investigators.

Abstract Background Previous Magnetic Resonance Imaging (MRI) studies of people with anorexia nervosa (AN) have shown differences in brain structure. This study aimed to provide preliminary extensions of this data by examining how different levels of appetitive restraint impact on brain volume. Methods Voxel based morphometry (VBM), corrected for total intracranial volume, age, BMI, years of education in 14 women with AN (8 RAN and 6 BPAN) and 21 women (HC) was performed. Correlations between brain volume and dietary restraint were done using Statistical Package for the Social Sciences (SPSS). Results Increased right dorsolateral prefrontal cortex (DLPFC) and reduced right anterior insular cortex, bilateral parahippocampal gyrus, left fusiform gyrus, left cerebellum and right posterior cingulate volumes in AN compared to HC. RAN compared to BPAN had reduced left orbitofrontal cortex, right anterior insular cortex, bilateral parahippocampal gyrus and left cerebellum. Age negatively correlated with right DLPFC volume in HC but not in AN; dietary restraint and BMI predicted 57% of variance in right DLPFC volume in AN. Conclusions In AN, brain volume differences were found in appetitive, somatosensory and top-down control brain regions. Differences in regional GMV may be linked to levels of appetitive restraint, but whether they are state or trait is unclear. Nevertheless, these discrete brain volume differences provide candidate brain regions for further structural and functional study in people with eating disorders.

Abstract Background The free-living nematode Caenorhabditis elegans makes a developmental decision based on environmental conditions: larvae either arrest as dauer larva, or continue development into reproductive adults. There is natural variation among C. elegans lines in the sensitivity of this decision to environmental conditions; that is, there is variation in the phenotypic plasticity of dauer larva development. We hypothesised that these differences may be transcriptionally controlled in early stage larvae. We investigated this by microarray analysis of different C. elegans lines under different environmental conditions, specifically the presence and absence of dauer larva-inducing pheromone. Results There were substantial transcriptional differences between four C. elegans lines under the same environmental conditions. The expression of approximately 2,000 genes differed between genetically different lines, with each line showing a largely line-specific transcriptional profile. The expression of genes that are markers of larval moulting suggested that the lines may be developing at different rates. The expression of a total of 89 genes was putatively affected by dauer larva or non-dauer larva-inducing conditions. Among the upstream regions of these genes there was an over-representation of DAF-16-binding motifs. Conclusion Under the same environmental conditions genetically different lines of C. elegans had substantial transcriptional differences. This variation may be due to differences in the developmental rates of the lines. Different environmental conditions had a rather smaller effect on transcription. The preponderance of DAF-16-binding motifs upstream of these genes was consistent with these genes playing a key role in the decision between development into dauer or into non-dauer larvae. There was little overlap between the genes whose expression was affected by environmental conditions and previously identified loci involved in the plasticity of dauer larva development.

Abstract Background Serial Analysis of Gene Expression (SAGE) is a powerful tool for genome-wide transcription studies. Unlike microarrays, it has the ability to detect novel forms of RNA such as alternatively spliced and antisense transcripts, without the need for prior knowledge of their existence. One limitation of using SAGE on an organism with a complex genome and lacking detailed sequence information, such as the hexaploid bread wheat Triticum aestivum, is accurate annotation of the tags generated. Without accurate annotation it is impossible to fully understand the dynamic processes involved in such complex polyploid organisms. Hence we have developed and utilised novel procedures to characterise, in detail, SAGE tags generated from the whole grain transcriptome of hexaploid wheat. Results Examination of 71,930 Long SAGE tags generated from six libraries derived from two wheat genotypes grown under two different conditions suggested that SAGE is a reliable and reproducible technique for use in studying the hexaploid wheat transcriptome. However, our results also showed that in poorly annotated and/or poorly sequenced genomes, such as hexaploid wheat, considerably more information can be extracted from SAGE data by carrying out a systematic analysis of both perfect and "fuzzy" (partially matched) tags. This detailed analysis of the SAGE data shows first that while there is evidence of alternative polyadenylation this appears to occur exclusively within the 3' untranslated regions. Secondly, we found no strong evidence for widespread alternative splicing in the developing wheat grain transcriptome. However, analysis of our SAGE data shows that antisense transcripts are probably widespread within the transcriptome and appear to be derived from numerous locations within the genome. Examination of antisense transcripts showing sequence similarity to the Puroindoline a and Puroindoline b genes suggests that such antisense transcripts might have a role in the regulation of gene expression. Conclusion Our results indicate that the detailed analysis of transcriptome data, such as SAGE tags, is essential to understand fully the factors that regulate gene expression and that such analysis of the wheat grain transcriptome reveals that antisense transcripts maybe widespread and hence probably play a significant role in the regulation of gene expression during grain development.

Abstract Background The nematode Strongyloides ratti has two adult phases in its lifecycle: one obligate, female and parasitic and one facultative, dioecious and free-living. The molecular control of the development of this free-living generation remains to be elucidated. Results We have constructed an S. ratti cDNA microarray and used it to interrogate changes in gene expression during the free-living phase of the S. ratti life-cycle. We have found very extensive differences in gene expression between first-stage larvae (L1) passed in faeces and infective L3s preparing to infect hosts. In L1 stages there was comparatively greater expression of genes involved in growth. We have also compared gene expression in L2 stages destined to develop directly into infective L3s with those destined to develop indirectly into free-living adults. This revealed relatively small differences in gene expression. We find little evidence for the conservation of transcription profiles between S. ratti and S. stercoralis or C. elegans. Conclusion This is the first multi-gene study of gene expression in S. ratti. This has shown that robust data can be generated, with consistent measures of expression within computationally determined clusters and contigs. We find inconsistencies between EST representation data and microarray hybridization data in the identification of genes with stage-specific expression and highly expressed genes. Many of the genes whose expression is significantly different between L1 and iL3s stages are unknown beyond alignments to predicted genes. This highlights the forthcoming challenge in actually determining the role of these genes in the life of S. ratti.

Purpose: The acute ingestion of a ketone monoester with the coingestion of a carbohydrate (KME + CHO) compared with carbohydrate (CHO) was investigated on cycling performance and cognitive performance in trained females., Methods: Using a two condition, placebo-controlled, double-blinded and crossover design, 12 trained females (mean ± SD: age, 23 ± 3 yr; height, 1.64 ± 0.08 m; mass, 65.2 ± 12.7 kg) completed a baseline assessment of cognitive performance (psychomotor vigilance testing (PVT), task switching, and incongruent flanker), followed by 6 × 5-min intervals at 40%, 45%, 50%, 55%, 60%, and 65% of their maximal power output (W max ) and then a 10-km time trial, concluding with the same assessments of cognitive performance. Participants consumed either 375 mg·kg -1 body mass of KME with a 6% CHO solution (1 g·min -1 of exercise) or CHO alone, across three boluses (50:25:25)., Results: Blood β-hydroxybutyrate concentrations averaged 1.80 ± 0.07 and 0.13 ± 0.01 mM during exercise in KME + CHO and CHO, respectively. Blood glucose decreased after drink 1 of KME + CHO (~15%; P = 0.01) but not CHO, and lactate concentrations were lower in KME + CHO at 50%, 55%, 60%, and 65% W max (all P < 0.05) compared with CHO. Despite these changes, no differences were found between conditions for time trial finishing times (KME + CHO, 29.7 ± 5.7 min; CHO, 29.6 ± 5.7 min; P = 0.92). However, only KME + CHO resulted in increases in psychomotor vigilance testing speed (~4%; P = 0.01) and faster reaction times (~14%; P < 0.01), speed (~15%; P < 0.01), and correct responses (~13%; P = 0.03) in the incongruent flanker during posttesting compared with CHO., Conclusions: The acute ingestion of a KME + CHO elevated blood β-hydroxybutyrate and lowered glucose and lactate across multiple time points during exercise compared with CHO. Although these changes did not affect physical performance, several markers of cognitive performance were improved by the addition of a KME in trained females., (Copyright © 2023 by the American College of Sports Medicine.)

Aim: This retrospective review examined the introduction of bubble Continuous Positive Airway Pressure (bCPAP) in resuscitating neonates in a rural hospital environment., Methods: A retrospective audit of all emergent neonatal presentations to a rural emergency department (ED) over a 5-year period prior to (pre) and a 3.5-year period following the introduction of bCPAP (post)., Results: Sixty-seven neonatal resuscitations (31 pre- and 36 post-introduction of bCPAP) were reviewed, having an average gestation of 37.4 weeks and birth weight of 3,110g, with no significant difference in characteristics between groups. Time in the ED was significantly longer post-bCPAP (202±93 vs 156±70 mins), but time applying T-piece assisted ventilation was significantly reduced (55±40 vs 94 ± 84 mins). There was an 11% reduction in the use of aeromedical retrieval and an 18% reduction in admissions to the regional level III neonatal intensive care unit (NICU) with a corresponding increase in admissions to local level II NICU., Conclusion: The introduction of bCPAP into a rural hospital setting is technically feasible and results in less time spent on technically demanding hand ventilation, fewer admissions to level III neonatal intensive care units and a reduction in the use of aeromedical retrieval assets., Competing Interests: Nil., (© PMA.)

Abstract: Parten, AL, Barker, GA, O'Neal, EK, and Waldman, HS. Seven-week accommodating resistance training improves Wingate peak power but not muscular strength or endurance in strength-trained females. J Strength Cond Res 37(9): 1789-1794, 2023-Accommodating resistance (AR) is a training technique that includes attaching elastic bands or chains to a loaded barbell to alter the resistance profile throughout the barbell movement. This study was the first to quantify the effects of AR versus a traditional resistance (TR) training program on changes in strength and power profiles in a trained female cohort. Resistance-trained (training history: 2.4 ± 1.4 years) females (age: 22.1 ± 3.0 years) completed baseline and postintervention tasks which included 1 repetition maximum (1RM) testing in the back squat (BS) and bench press (BP), a repetitions to failure in the BP (60% of 1RM), and 1 30-s Wingate test. After baseline testing, subjects were stratified (based on relative strength) into either the AR ( n = 9) or TR ( n = 10) group and then completed a supervised, 7-week training intervention. Both groups improved their 1RM in both lifts, but no statistical differences were found between groups in 1RM for BS, BP, or BP to failure ( p > 0.05). However, the AR group increased Wingate peak power (837 ± 221 to 901 ± 215 W; p = 0.04), whereas TR (868 ± 244 to 8,343 ± 182 W; p = 0.47) did not. This study supports AR with lighter relative barbell load incurs similar strength adaptations as TR. For coaches training athletes concerned with power, AR may be advantageous for improving rate of force development as demonstrated by large increases in peak Wingate power., (Copyright © 2023 National Strength and Conditioning Association.)

A prediction that faunal recovery of a marine aggregate extraction site subjected to high dredging intensity was likely to take 15-20 years was investigated. Samples were collected at the high dredging intensity site and two reference sites in 2011 (15 years post-dredging). Results indicated that the high site had similar sediment characteristics to the reference sites by 2011. Macrofaunal data analyses showed no difference between the values of all calculated univariate measures (abundance, number of taxa, biomass and evenness) between the high and reference sites. Multivariate analyses found that the macrofaunal community at the high site was comparable to those of the reference sites by 2011. Overall, the results supported the predicted recovery time. The findings of the study suggest that persistent physical impacts prolonged the biological recovery of the high site., (Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.)

High throughput process development offers unique approaches to explore complex process design spaces with relatively low material consumption. Batch chromatography is one technique that can be used to screen chromatographic conditions in a 96-well plate. Typical batch chromatography workflows examine variations in buffer conditions or comparison of multiple resins in a given process, as opposed to the assessment of protein loading conditions in combination with other factors. A modification to the batch chromatography paradigm is described here where experimental planning, programming, and a staggered loading approach increase the multivariate space that can be explored with a liquid handling system. The iterative batch chromatography (IBC) approach is described, which treats every well in a 96-well plate as an individual experiment, wherein protein loading conditions can be varied alongside other factors such as wash and elution buffer conditions. As all of these factors are explored in the same experiment, the interactions between them are characterized and the number of follow-up confirmatory experiments is reduced. This in turn improves statistical power and throughput. Two examples of the IBC method are shown and the impact of the load conditions are assessed in combination with the other factors explored., (Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Intracellular barriers to adeno-associated virus (AAV) transduction may limit gene delivery. We screened a short interfering RNA (siRNA) library targeting 5,520 genes to help identify pathways that modulate AAV transduction of human endothelium. In replicate screening, 50 pools (three siRNAs per gene) resulted in greater than eightfold reporter gene expression enhancement. Single siRNA confirmation tests demonstrated that at least one siRNA from each of the top 10 pools provided greater than twofold enhancement. Several siRNAs when used together resulted in additive effects and two of the most potent siRNA sequences were enhancers in cultured airway epithelium. However, enhanced transduction was not correlated with mRNA knockdown by quantitative real time PCR, indicating an off-target mechanism. In fact, four of the five most potent siRNAs contained a consensus hexamer region 5'-UGUUUC-3' at positions 2-7 of the antisense strand. The point mutation U4A within this region (but not mutations at positions 1 or 14) disrupted transduction enhancement, indicating a microRNA (miRNA)-like mechanism. Transcription profiling indicated that the hexamer also resulted in perturbation of the interferon pathway via reduced interferon-induced protein 44-like (IFI44L), interferon-inducible myxovirus resistance 1 (MX1), and interferon-induced protein with tetratricopeptide repeats (IFIT5) mRNAs. Direct interferon (α, β, and ω) receptor 2 (IFNAR2) knockdown resulted in greater than twofold transduction enhancement. In addition to providing insight into AAV biology and enhanced transduction, the results demonstrate certain beneficial siRNA off-target effects.

Some barriers to DNA lipofection are well characterized; however, there is as yet no method of finding unknown pathways that impact the process. A druggable genome small-interfering RNA (siRNA) screen against 5,520 genes was tested for its effect on lipofection of human aortic endothelial cells (HAECs). We found 130 gene targets which, when silenced by pooled siRNAs (three siRNAs per gene), resulted in enhanced luminescence after lipofection (86 gene targets showed reduced expression). In confirmation tests with single siRNAs, 18 of the 130 hits showed enhanced lipofection with two or more individual siRNAs in the absence of cytotoxicity. Of these confirmed gene targets, we identified five leading candidates, two of which are isoforms of the regulatory subunit of protein phosphatase 2A (PP2A). The best candidate siRNA targeted the PPP2R2C gene and produced a 65% increase in luminescence from lipofection, with a quantitative PCR-validated knockdown of approximately 76%. Flow cytometric analysis confirmed that the silencing of the PPP2R2C gene resulted in an improvement of 10% in transfection efficiency, thereby demonstrating an increase in the number of transfected cells. These results show that an RNA interference (RNAi) high-throughput screen (HTS) can be applied to nonviral gene transfer. We have also demonstrated that siRNAs can be co-delivered with lipofected DNA to increase the transfection efficiency in vitro.

Fluorescence scanning confocal microscopy was used in parallel with batch uptake and breakthrough measurements of transport rates to study the effect of ionic strength on the uptake of lysozyme into SP Sepharose FF. In all cases the adsorption isotherms were near-rectangular. As described previously, the intraparticle profiles changed from slow-moving self-sharpening fronts at low salt concentration, to fast-moving diffuse profiles at high salt concentration, and batch uptake rates correspondingly increased with increasing salt concentration. Shrinking core and homogeneous diffusion frameworks were used successfully to obtain effective diffusivities for the low salt and high salt conditions, respectively. The prediction of column breakthrough was generally good using these frameworks, except for low-salt uptake results. In those cases, the compressibility of the stationary phase coupled with the shrinking core behavior appears to reduce the mass transfer rates at particle-particle contacts, leading to shallower breakthrough curves. In contrast, the fast uptake rates at high ionic strength appear to reduce the importance of mass transfer limitations at the particle contacts, but the confocal results do show a flow rate dependence on the uptake profiles, suggesting that external mass transfer becomes more limiting at high ionic strength. These results show that the complexity of behavior observable at the microscopic scale is directly manifested at the column scale and provides a phenomenological basis to interpret and predict column breakthrough. In addition, the results provide heuristics for the optimization of chromatographic conditions.

Objective: In this preliminary study we tested the effect of short-term carbohydrate supplementation on carbohydrate oxidation and walking performance in peripheral arterial disease., Methods: Eleven patients with peripheral arterial disease and intermittent claudication and 8 healthy control subjects completed several weeks of baseline exercise testing, then were given supplementation for 3 days with a carbohydrate solution and placebo. Maximal walking time was assessed with a graded treadmill test. Carbohydrate oxidation during a submaximal phase of this test was measured with indirect calorimetry. At the end of baseline testing a biopsy specimen was taken from the gastrocnemius muscle, and the active fraction of pyruvate dehydrogenase complex activity was determined., Results: Carbohydrate supplementation resulted in a significant increase in body weight and carbohydrate oxidation during exercise in patients with intermittent claudication and control subjects. Maximal walking time decreased by 3% in control subjects, whereas it increased by 6% in patients with intermittent claudication (group x treatment interaction, P < .05). There was a wide range of performance responses to carbohydrate supplementation among patients with claudication (-3%-37%). This effect was greater in poorer performers, and was negatively correlated (P < .05) with muscle pyruvate dehydrogenase complex activity., Conclusion: Preliminary data suggest that carbohydrate oxidation during exercise might contribute to exercise intolerance in more dysfunctional patients with intermittent claudication and that carbohydrate supplementation might be an effective therapeutic intervention in these patients.

In the present study, we tested the hypothesis that walking intolerance in intermittent claudication (IC) is related to both slowed whole body oxygen uptake (VO2) kinetics and altered activity of the active fraction of the pyruvate dehydrogenase complex (PDCa) in skeletal muscle. Ten patients with IC and peripheral arterial disease [ankle/brachial index (ABI)=0.73 +/- 0.13] and eight healthy controls (ABI=1.17 +/- 0.13) completed three maximal walking tests. From these tests, averaged estimates of walking time, peak VO2 and the time constant of VO2 (tau) during submaximal walking were obtained. A muscle sample was taken from the gastrocnemius medialis muscle at rest and analysed for PDCa and several other biochemical variables. Walking time and peak VO2 were approx. 50% lower in patients with IC than controls, and tau was 2-fold higher (P<0.05). tau was significantly correlated with walking time (r=-0.72) and peak VO2 (r=-0.66) in patients with IC, but not in controls. PDCa was not significantly lower in patients with IC than controls; however, PDCa tended to be correlated with tau (r=-0.56, P=0.09) in patients with IC, but not in controls (r=-0.14). A similar correlation was observed between resting ABI and tau (r=-0.63, P=0.05) in patients with IC. These data suggest that the impaired VO2 kinetics contributes to walking intolerance in IC and that, within a group of patients with IC, differences in VO2 kinetics might be partly linked to differences in muscle carbohydrate oxidation.

Scanning confocal fluorescence microscopy and multiphoton fluorescence microscopy were used to image the uptake of the protein lysozyme into individual ion exchange chromatography particles in a packed bed in real time. Self-sharpening concentration fronts penetrating into the particles were observed at low salt concentrations in all of the adsorbents studied, but persisted to 100 mM ionic strength only in some materials. In other adsorbents, diffuse profiles were seen at these higher salt concentrations, with the transition region exhibiting a pronounced fluorescence peak at the front at intermediate salt concentrations. These patterns in the uptake profiles are accompanied by significant increases in protein uptake rates that are also seen macroscopically in batch uptake experiments. The fluorescence peak appears to be a concentration overshoot that may develop, in part, from an electrokinetic contribution to transport that also enhances the uptake rate. Further evidence for an electrokinetic origin is that the effect is correlated with high adsorbent surface charge densities. Predictions of a mathematical model incorporating the electrokinetic effect are in qualitative agreement with the observations. These findings indicate that mechanisms other than diffusion contribute to protein transport in oppositely charged porous materials and may be exploited to achieve rapid uptake in process chromatography.

A means for distinguishing between clinical isolates of Renibacterium salmoninarum that is based on the PCR amplification of length polymorphisms in the tRNA intergenic spacer regions (tDNA-ILPs) was investigated. The method used primers specific to nucleotide sequences of R. salmoninarum tRNA genes and tRNA intergenic spacer regions that had been generated by using consensus tRNA gene primers. Twenty-one PCR products were sequenced from five isolates of R. salmoninarum from the United States, England, and Scotland, and four complete tRNA genes and spacer regions were identified. Sixteen specific PCR primers were designed and tested singly and in all possible pairwise combinations for their potential to discriminate between isolates from recent clinical outbreaks of bacterial kidney disease (BKD) in the United Kingdom. Fourteen of the isolates were cultured from kidney samples taken from fish displaying clinical signs of BKD on five farms, and some of the isolates came from the same farm and at the same time. The tDNA-ILP profiles separated 22 clinical isolates into nine groups and highlighted that some farms may have had more than one source of infection. The grouping of isolates improved on the discriminatory power of previously reported typing methods based on randomly amplified polymorphic DNA analysis and restriction fragment length profiles developed using insertion sequence IS994. Our method enabled us to make divisions between closely related clinical isolates of R. salmoninarum that have identical exact tandem repeat (ETR-A) loci, rRNA intergenic spacer sequences, and IS994 profiles.

Background: There has been a trend toward advocating earlier repair of tetralogy of Fallot and avoiding palliative procedures. The impact of this trend on perioperative outcomes has not been adequately documented., Methods: Data from consecutive patients undergoing repair of tetralogy of Fallot at less than 18 months of age from May 1987 to September 1994 were reviewed. Independent factors associated with duration of stay in the intensive care unit were sought., Results: Repair was performed in 89 infants at a median age of 13 months (range, 15 days to 18 months). A systemic-pulmonary artery shunt was present in 24% of patients. Mean duration of cardiopulmonary bypass was 119+/-37 minutes; 63% of patients received a transannular patch. There were six deaths (7%), all occurring less than 48 hours after repair. The median duration of stay in the intensive care unit was 5 days (range, 1 day to 8 months). Significant independent factors associated with increasing length of intensive care unit stay included younger age at repair, previous shunt, malformation syndrome, increased total dose and number of inotropic agents used, and respiratory complications. Hemodynamic variables serially recorded in the first 48 hours after repair were independently associated with death or prolonged (>7 days) duration of stay., Conclusions: Although outcomes after repair of tetralogy of Fallot in infants are good, both younger age at repair and previous palliative procedures were associated with longer duration of stay in the intensive care unit.

1. The sodium-dependent amino acid transport systems responsible for proline, glycine and glutamine transport, together with the sodium-independent systems for leucine and tryptophan, have been investigated in isolated bovine chondrocytes by inhibition studies and ion replacement. Each system was characterized kinetically. 2. Transport via system A was identified using the system-specific analogue alpha-methylaminoisobutyric acid (MeAIB) as an inhibitor of proline, glycine and glutamine transport. 3. Uptake of proline, glycine and glutamine via system ASC was identified by inhibition with alanine or serine. 4. System Gly was identified by the inhibition of glycine transport with excess sarcosine (a substrate for system Gly) whilst systems A and ASC were inhibited. This system, having a very limited substrate specificity and tissue distribution, was also shown to be Na+ and Cl- dependent. Evidence for expression of the system Gly component GLYT-1 was obtained using the reverse transcriptase-polymerase chain reaction (RT-PCR). 5. System N, also of narrow substrate specificity and tissue distribution, was shown to be present in chondrocytes. Na+-dependent glutamine uptake was inhibited by high concentrations of histidine (a substrate of system N) in the presence of excess MeAIB and serine. 6. System L was identified using the system specific analogue 2-aminobicyclo(2,2, 1)heptane-2-carboxylic acid (BCH) and D-leucine as inhibitors of leucine and tryptophan transport. 7. The presence of system T was tested by using leucine, tryptophan and tyrosine inhibition. It was concluded that this system was absent in the chondrocyte. 8. Kinetic analysis showed the Na+-independent chondrocyte L system to have apparent affinities for leucine and tryptophan of 125 +/- 27 and 36 +/- 11 microM, respectively. 9. Transport of the essential amino acids leucine and tryptophan into bovine chondrocytes occurs only by the Na+-independent system L, but with a higher affinity than the conventional L system.

We have conducted a retrospective survey of 79 children out of a total hospital asthmatic patient population of 2,412, admitted over a 32 month period to the ICU for the management of severe status asthmaticus. All patients were in severe respiratory distress with CO2 retention; 19 required mechanical ventilation due to increasing fatigue and worsening bronchospasm, having failed to respond to either inhaled or IV bronchodilator therapy. All patients were ventilated at slow rates (less than 12 min) and their airway pressure (Paw) was deliberately kept below 45 cmH2O, while accepting a PaCO2 in the 45-60 mmHg range, as long as the pH was compensated. Although two patients developed pneumothoraces while on positive pressure ventilation, these were resolved without incidents. Five patients who had mediastinal or subcutaneous air leaks prior to intubation did not develop pneumothoraces. Following the initiation of mechanical ventilation, IV beta-agonist therapy was increased in order to reverse the bronchospasm and reduce the duration of mechanical ventilation. Mean duration of intubation was 42 hours. Fourteen of the 19 patients were weaned and extubated within 48 hours. All patients survived without sequelae. We conclude that a degree of controlled "hypoventilation" by deliberately choosing Paw less than 45 cmH2O can be successfully used to ventilate children with severe status asthmaticus with a reduced rate of pressure-related complications.

Scoliosis associated with muscular dystrophy frequently necessitates surgical stabilization of the spine. The timing of surgery usually is based on the degree of spinal angulation. Pulmonary function, which deteriorates with age in children with muscular dystrophy, should also be an important consideration in this timing. In a retrospective study of 48 patients who underwent spinal stabilization, preoperative respiratory function tests were correlated with postoperative respiratory complications. The percentage of predicted vital capacity provided the best indicator of outcome and values of less than 30% were associated with major respiratory complications. Spinal fixation failed to arrest the decline in respiratory function in these patients, but it seemed to slow the rate of deterioration compared with preoperative changes. Evaluation of pulmonary function should play a major role in the timing of surgical intervention in muscular dystrophy.

This is a report of a case of complete congenital tracheal stenosis confirmed by tracheobronchogram. The stenosis also involved the origin of the right main bronchus. The membranous portion of the trachea was absent. It was repaired through a sternotomy and right thoracotomy aided by partial cardiopulmonary bypass. The posterior trachea was opened from larynx to carina and on into the right main bronchus, and each posterior tracheal edge was sewn to the anterior wall of the esophagus with a running Prolene suture. Three months after repair bronchoscopy showed that the new membranous trachea was epithelialized and the entire airway was of good caliber; the only problem was a diffuse tracheomalacia. He died in his seventh postoperative month after a major airway complication due to tracheotomy, which occurred after an elective bronchoscopy. It is obvious that this operation is technically feasible. It was hoped that his airway would become sufficiently stable to allow the tracheotomy tube to be removed at some time in the future.

Femoral artery thrombosis remains a well-known complication after cardiac catheterization. A study was undertaken to assess the efficacy of thrombolytic therapy for this complication. A total of 526 consecutive infants and children were prospectively evaluated after cardiac catheterization, and the medical charts of 42 patients who required femoral artery thrombectomy between 1975 and 1985 were reviewed. In the prospective study, patients were given a bolus injection of heparin, 150 U/kg, at the time the artery was entered. Patients with persistently absent or diminished pulse 2 hours after catheterization received a second bolus injection of 50 U/kg followed by an infusion of 20 U/kg/hr heparin for a maximum of 48 hours. If the affected leg pulse was absent or reduced and the systolic Doppler blood pressure was less than two thirds that of the unaffected leg, thrombolytic therapy was begun. In the 42 patients with surgical thrombectomy, there were no serious complications of surgery. Forty-five of the 526 patients (8.6%) had a decreased or absent pulse after catheterization. Of these 45 patients, 32 (71.1%) improved with systemic heparinization only. Thirteen patients (28.9%) had a persistently absent pedal pulse suggesting femoral artery thrombosis, despite continuous heparinization. Eleven patients were successfully treated with thrombolytic therapy and two required surgical thrombectomy. Intraarterial balloon dilatation procedures were performed in 8 of these 13 patients. Prothrombin time was prolonged (11.5 +/- 1.06 to 52.3 +/- 40.4 seconds; p less than 0.025) and fibrinogen levels were significantly reduced (2.25 +/- 0.79 to 1.52 +/- 0.52 gm/dl; p less than 0.01) during therapy. There were no serious complications, although four patients bled from the groin entry site.(ABSTRACT TRUNCATED AT 250 WORDS)

To determine whether surgical repair of congenital diaphragmatic hernia (CHD) results in improvement in respiratory mechanics, we measured respiratory system compliance in nine patients (five survivors and four nonsurvivors) before and after operation. In all nine infants, CHD was diagnosed within 6 hours of life, and surgical repair was through an abdominal approach after a period of stabilization. Measurements were made noninvasively, using the passive expiratory flow-volume technique. In only one of the nine infants did compliance immediately improve after surgical repair, and in another it showed no change. Both of these infants survived, with an uneventful postoperative course. In the remaining seven infants, however, postoperative compliance immediately decreased to 10% to 77% from the preoperative value. The four infants with more than 50% decrease in compliance died with increasing hypoxemia and acidosis. These results suggest that respiratory mechanics in CHD, far from improving, frequently deteriorate as a result of repair of the hernia. The role of urgent surgery in this malformation should be reevaluated.

A retrospective analysis has been performed of children who have undergone cardiac operations during the past 6 years to determine the clinical presentation and management of acute hepatic failure (AHF) in the postoperative period. Eleven patients had a clinical picture of AHF with jaundice, elevation of the levels of serum glutamic oxaloacetic transaminase (SGOT) and serum ammonia, and marked prolongation of the prothrombin time associated with failure of hemostasis. Hypoglycemia developed in seven. All patients had evidence of low cardiac output and acute renal failure. Patients with AHF had evidence of reduced hepatic perfusion during the previous 24 hours with reduced mean arterial pressure and elevated central venous pressure. Six children died of myocardial failure. A modified Fontan procedure was performed in six children, of whom four died. All had a right atrial pressure of 21 torr or greater. Five children survived the acute episode of hepatic failure. The importance of early diagnosis and effective management of complications such as hypoglycemia and the bleeding tendency are emphasized.

The effects of the nonselective beta blocker, propranolol, on coarctectomy-induced hypertension were evaluated relative to changes in cardiac function, sympathetic tone, and plasma renin activity (PRA). A randomized, placebo-controlled, double-blind, age-stratified design was employed. Propranolol (n = 11, mean age 9.4 years) or placebo (n = 12, mean age 10.2 years) was started 2 days before surgery and continued until 6 days after surgery. In patients on placebo, systolic and diastolic blood pressure, heart rate, and cardiac index increased rapidly and peaked within 1 day after surgery. Over the ensuing days these increases gradually abated. Plasma epinephrine and PRA increased markedly within 12 hours after surgery, but returned quickly toward preoperative levels. In contrast, plasma norepinephrine increased more gradually and remained elevated longer. In patients on propranolol, systolic blood pressure, heart rate, cardiac index and PRA showed only negligible increases. However, diastolic blood pressure, increased even faster with propranolol than with placebo but to the same extent. Plasma catecholamines showed similar increases on the two treatments. Only in the placebo group was the code broken in the intensive care unit because of hypertension uncontrolled by sodium nitroprusside; this occurred in 6 of 12 patients. We conclude that nonselective beta blockade ameliorates the hyperdynamic circulation and increase in systolic blood pressure following coarctectomy. The initial increase in diastolic blood pressure following surgery in the propranolol group may have been caused by vascular beta-2-receptor blockade resulting in unopposed alpha-receptor-mediated vasoconstriction.

We evaluated a new pulse oximeter designed to monitor beat-to-beat arterial oxygen saturation (SaO2) and compared the monitored SaO2 with arterial samples measured by co-oximetry. In 40 critically ill children (112 data sets) with a mean age of 3.9 years (range 1 day to 19 years), SaO2 ranged from 57% to 100%, and PaO2 from 27 to 128 mm Hg, heart rates from 85 to 210 beats per minute, hematocrit from 20% to 67%, and fetal hemoglobin levels from 1.3% to 60%; peripheral temperatures varied between 26.5 degrees and 36.5 degrees C. Linear correlation analysis revealed a good agreement between simultaneous pulse oximeter values and both directly measured SaO2 (r = 0.95) and that calculated from measured arterial PaO2 (r = 0.95). The device detected several otherwise unrecognized drops in SaO2 but failed to function in four patients with poor peripheral perfusion secondary to low cardiac output. Simultaneous measurements with a tcPO2 electrode showed a similarly good correlation with PaO22 (r = 0.91), but the differences between the two measurements were much wider (mean 7.1 +/- 10.3 mm Hg, range -14 to +49 mm Hg) than the differences between pulse oximeter SaO2 and measured SaO2 (1.5% +/- 3.5%, range -7.5% to -9%) and were not predictable. We conclude that pulse oximetry is a reliable and accurate noninvasive device for measuring saturation, which because of its rapid response time may be an important advance in monitoring changes in oxygenation and guiding oxygen therapy.

Septicemia is common in patients in the pediatric intensive care unit (ICU) who have nasotracheal tubes. Although it is frequently caused by middle ear effusion (MEE), pneumatic otoscopy is not routinely performed in these patients. To demonstrate the value of this procedure, 46 pediatric ICU patients with nasotracheal tubes were followed daily with pneumatic otoscopy for 11 to 98 days and compared with 25 controls without nasotracheal tubes, 12 of whom had nasogastric tubes. Myringotomy was performed whenever blood culture became positive. MEE was significantly more frequent in patients with nasotracheal tubes (87%) than in patients with controls (23%) and occurred first on the side of intubation. Blood bacteria were identical to middle ear pathogens in 80% of patients. Nasogastric tubes were not significant in causing MEE. The high incidence of MEE resulting from nasotracheal intubation indicates the importance of including pneumatic otoscopy in the daily examination of these high-risk patients.

The synthetic inotropic agent, dobutamine, has reportedly increased cardiac output in adults after cardiopulmonary bypass with minimal side effects. Its use in children, after surgical correction of congenital heart disease, was tested by infusing the drug at 1, 4, 7, and 10 micrograms/kg x min in 11 children. While significant increases in cardiac index above control (23, 23, and 16% at 4, 7, and 10 micrograms/kg x min, respectively) were observed, this was achieved at the expense of significant increases in heart rate (15, 24, and 10%). This increase in heart rate (47% in one child) necessitated discontinuing the infusion in 4 subjects. There were also significant increases in systolic and mean blood pressure with no change in stroke volume or peripheral vascular resistance. The authors conclude that in children, dobutamine is an effective inotropic agent acting principally by stimulating beta 1-receptors in the myocardium producing a predominantly chronotropic effect without significant changes in peripheral vascular resistance. Given the intrinsically higher heart rate of children, the levels of tachycardia produced by the drug in some instances reach unacceptable levels and as such, may make dopabutamine unsuitable for use in children after cardiopulmonary bypass.

We retrospectively evaluated the clinical and pathologic effects of hypothermia and high-dose barbiturate therapy on hypoxic/ischemic cerebral injury after near-drowning in children. Of 40 near-drowned patients admitted to the ICU, 13 died, seven had permanent cerebral damage, and 20 survived. Twenty-four patients (group 1) were treated with a regime of hyperventilation, hypothermia, and high-dose phenobarbitone while intracranial pressure (ICP) was continuously monitored. Of ten who died in this group, three were diagnosed as having cerebral death shortly after admission; autopsy revealed severe cerebral edema with herniation. The remaining seven nonsurvivors had severe cerebral hypoxia without raised ICP and had the features of severe adult respiratory distress syndrome and hypoxic/ischemic damage to other organs. Six of these seven patients developed septicemia which was invariably associated with a profound neutropenia. Sixteen patients (group 2) were treated with a similar protocol but without hypothermia. Three of these patients died but only one developed septicemia. Neutropenia after resuscitation from near-drowning seemed to indicate a poor prognosis; the mean polymorphonuclear leukocyte count in nonsurvivors (1.9 +/- 0.5 X 10(9) cell/L) was significantly (p less than .01) lower than that in survivors (6.4 +/- 1.1 X 10(9) cell/L). Hypothermia was associated with a decreased number of circulating PMNs but did not increase the number of neurologically intact survivors. Similarly, although barbiturates may control ICP, their use did not improve outcome. Because severe cerebral edema and herniation after near-drowning is usually associated with irreversible brain damage, measures to control brain swelling such as hypothermia and barbiturates will be of little benefit.(ABSTRACT TRUNCATED AT 250 WORDS)

The percentage of change in tracheal diameter (TD% change), as assessed by an objective radiological measurement, was used along with a simple subjective clinical score to assess response to therapy in upper airway obstruction in 14 patients with acute infectious croup. Studies were performed on the 14 patients, each of whom was randomly assigned to one of two treatment groups: distilled water or racemic epinephrine (RE), both being nebulized and delivered by manual IPPB. The objective radiological assessment and the subjective clinical score both confirmed that RE is significantly (p less than 0.005) more effective than distilled water in the acute relief of upper airway obstruction. The more precise radiological assessment may be of value in determining objectively better drug therapy for infectious croup.

Fifty-eight infants with congenital diaphragmatic hernia presenting within the first 6 hours of life, who underwent surgical repair, were analysed prospectively in order to produce a reliable index of severity of disease that would reliably predict eventual outcome. All were treated with paralysis hyperventilation and intravenous (IV) isoproterenol for the first 48 hours. There were 30 survivors and 28 deaths in this series (mortality 48%). Using arterial PCO2 values measured 2 hours after surgical repair and correlating them with an index of mechanical ventilation (mean airway pressure and respiratory rate), we have been able to clearly define two groups of diaphragmatic hernia based on their response to IPPV. The first group, with CO2 retention and severe preductal shunting, was unresponsive to hyperventilation with high rates and pressures; the mortality was 90%. The second group responded well to hyperventilation and demonstrated reversable ductal shunting only. Survival in this group was 97%. Only four patients out of 58 exhibited the "honeymoon period," with a period of stability followed by severe ductal shunting. Arterial CO2 accurately reflects the degree of lung development in this disease and separates those patients with severe pulmonary hypoplasia, where the outcome is invariably fatal, from those with a well-developed contralateral lung where there is excellent potential for survival.

The hemodynamic response to increasing left atrial pressure by volume loading was evaluated in 70 children during the first 24 hours after repair of congenital cardiac defects. The children were grouped into four diagnostic categories: atrial septal defect or pulmonary valve stenosis (n = 8), ventricular septal defect (n = 36), complete transposition after Mustard's operation (n = 13), and tetralogy of Fallot (n = 13). Within 2 hours of bypass, both cardiac index and left ventricular stroke work index were adequate and increased appropriately with volume loading in all four diagnostic groups. The atrial septal defect group demonstrated a similar response to volume loading 4 and 24 hours after bypass. However, the other three diagnostic groups had a higher filling pressure, lower cardiac index and stroke work index, and a depressed response to increasing preload 4 hours postoperatively, which indicated a deterioration in cardiac performance. The deterioration was maximal between 4 and 12 hours after bypass, and performance tended to recover 24 hours postoperatively. The transposition group had a more profound depression in cardiac performance than the other two groups. Within the ventricular septal defect group, smaller children (body surface area less than 0.36 m2) had a more profound depression in performance than larger children. These results demonstrate a significant alteration in cardiac performance during the first 24 hours after repair of congenital cardiac defects in children. These changes should be considered when postoperative management is being planned.