Interfacial Tensions, Solubilities, and Transport Properties of the H2/H2O/NaCl System: A Molecular Simulation Study.

Data for several key thermodynamic and transport properties needed for technologies using hydrogen (H2), such as underground H2 storage and H2O electrolysis are scarce or completely missing. Force field-based Molecular Dynamics (MD) and Continuous Fractional Component Monte Carlo (CFCMC) simulations are carried out in this work to cover this gap. Extensive new data sets are provided for (a) interfacial tensions of H2 gas in contact with aqueous NaCl solutions for temperatures of (298 to 523) K, pressures of (1 to 600) bar, and molalities of (0 to 6) mol NaCl/kg H2O, (b) self-diffusivities of infinitely diluted H2 in aqueous NaCl solutions for temperatures of (298 to 723) K, pressures of (1 to 1000) bar, and molalities of (0 to 6) mol NaCl/kg H2O, and (c) solubilities of H2 in aqueous NaCl solutions for temperatures of (298 to 363) K, pressures of (1 to 1000) bar, and molalities of (0 to 6) mol NaCl/kg H2O. The force fields used are the TIP4P/2005 for H2O, the Madrid-2019 and the Madrid-Transport for NaCl, and the Vrabec and Marx for H2. Excellent agreement between the simulation results and available experimental data is found with average deviations lower than 10%.

Effects of free and nano-encapsulated bovine lactoferrin on the viability and acid production by Streptococcus mutans biofilms.

Tooth decay is one of the most common diseases that humans face during their lifetime. Streptococcus mutans is one of the most critical factors of early tooth decay. These bacteria may produce biofilms in the mouth, which are more resistant to antimicrobial agents. Streptococcus mutans may also demineralize tooth enamel by producing lactic acid. In this study, the effect of nanoliposomes containing lactoferrin at three different concentrations (1·5, 3 and 6 mg ml-1 ) on the biofilm formed by S. mutans was investigated. Nanoliposomes were prepared using the thin-layer hydration method. An active attachment model was used to evaluate biofilm and lactic acid production. The results showed that nano-encapsulated lactoferrin could reduce CFU of biofilm more effectively than free lactoferrin. Lactoferrin-containing nanoliposomes also significantly reduced lactic acid production by S. mutans. Therefore, nano-encapsulated lactoferrin may be used along with other dental caries control methods to increase anti-caries efficacy.

EFFECTS OF EXERCISE ON MIR-29 AND IGF-1 EXPRESSION AND LIPID PROFILE IN THE HEART OF OVARIECTOMIZED RAT.

INTRODUCTION: Menopause increases the risk of cardiovascular disease in women. The aims of the present study were to evaluate the effects of swimming training on cardiac histology and expression of miR-29 and IGF-1 in the ovariectomized rats. MATERIALS AND METHODS: Thirty female Wistar rats were divided into sham and ovariectomized groups: sedentary control (OVX) and trained with 8 weeks exercise (OVX.E). On 57th day, blood was collected and used for lipid profile measurement. In addition, heart tissue was analyzed by reverse transcription-polymerase chain reaction for IGF-1 mRNA and miR-29, and studied for histopathological changes. RESULTS: Ovariectomy significantly decreased miR-29 and IGF-1 expression in the heart compared to sham animals group (p<0.05). Exercise training increased miR-29 and IGF-1 expression in the trained rats and improved histology and lipid profile compared with OVX group (p<0.05). CONCLUSION: Estrogen deficiency could lead to cardiac fibrosis through deregulation miR-29 and IGF-1 expression. The findings of the current study suggests a protective effect of exercise on heart against fibrotic changes in ovariectomized rats and support a potential preventive value of exercise in improving cardiac function after menopause.

The effect of 2 mMol glutamine supplementation on HSP70 and TNF-α release by LPS stimulated blood from healthy children.

OBJECTIVE: Glutamine has been shown to promote heat shock protein 70 (HSP70) release both within experimental in vitro models of sepsis (2-10 mM) and in adults post trauma (0.5 g/kg), although the efficacy varies and is dependent on the model used. The effect of glutamine supplementation on HSP70 release in children is less clear. Therefore, the aim of this study was to investigate the effect of 2 mM glutamine added to incubation media on HSP70 and inflammatory mediator release in an in vitro model of paediatric sepsis using whole blood from healthy paediatric volunteers. METHODS: An in vitro whole blood endotoxin stimulation model using 1 µg/ml lipopolysaccharide (LPS) over a 24 h time period was used to investigate the effects of 2 mM glutamine on HSP70 and inflammatory mediator release in healthy children. RESULTS: The addition of 2 mM glutamine to the incubation media significantly increased HSP70 release over time (p < 0.05). This was associated with an early pro-inflammatory effect on TNF-α release at 4 h (p < 0.005) which was not seen at 24 h. There was a non significant trend towards higher levels of IL-6 and IL-10 following the addition of 2 mM glutamine, which appears to differ from the response reported in adult and animal models. CONCLUSION: Glutamine supplementation of incubation media promotes HSP70 and early TNF- α release in an in vitro model using blood samples from healthy children.

In vitro antitumor activity of parent and nano-encapsulated mono cobalt-substituted Keggin polyoxotungstate and its ctDNA binding properties.

The parent and nanosized starch, and lipid encapsulated K6[SiW11O39Co(H2O)]·nH2O (abbreviated as SEP, LEP and SiW11Co, respectively), as potent antitumor candidates, were synthesized and characterized by FT-IR spectroscopy, ICP, TG analysis, SEM and TEM images. The results show that the SiW11Co retains its parent structure after encapsulation by starch and lipid nanoparticles. Antitumor activity tests of SiW11Co and its encapsulated forms were carried out on two types of human cancer cells, MCF-7 and HEK-293 by MTT method. The encapsulated forms exhibited the higher antitumor activity compared to the parent SiW11Co. However, this observed enhancement for the lipid encapsulated form is more than the starch counterpart, which can be related to its smaller size. These results showed that these compounds can be novel antitumor candidates. The calf thymus DNA (abbreviated as ctDNA) binding ability of SiW11Co was also investigated, using UV-Vis absorption spectroscopy, fluorescence quenching and fluorescence Scatchard plots. Absorption spectra tracing reveal 10% hyperchromism for SiW11Co. The values of 1.8×10(4) and 1.2×10(4)M(-1) were obtained for association binding constant of SiW11Co to ctDNA at R⩾1 and R<1, respectively (R is defined as the mole ratio of SiW11Co to ctDNA). It was shown that the interaction of SiW11Co with ctDNA depended on the R values. The obtained results of absorption titration rejected the intercalating binding mode and suggest the groove or outside stacking binding for SiW11Co. These results were authenticated by fluorescence quenching experiments and scatchard plots.

Glutamine depletion and heat shock protein 70 (HSP70) in children with meningococcal disease.

BACKGROUND & AIMS: Heat shock proteins are classified into six main families, of which HSP70 is the best studied. HSP70 is postulated to modulate the immune/inflammatory response in critical illness. Glutamine promotes HSP70 release, however, little is known about the relationship between glutamine and HSP70 in paediatric critical illness. We therefore aimed to describe plasma levels of HSP70, inflammatory mediators and glutamine in critically ill children. METHODS: A clinical audit identified 143 children with severe meningococcal disease, 78 convalescent children, in addition to 35 healthy paediatric controls. Stored plasma was used to measure plasma concentrations of HSP70, inflammatory mediators and glutamine. RESULTS: HSP70 was significantly increased on admission (n = 143, mean 26.7 ng/ml; ±SD 79.95) compared with convalescence (n = 78, mean 3.16 ng/ml; ±SD 5.67). Glutamine levels were low (n = 132, mean 0.31 mmol/l; ±SD 0.13), which continued in convalescence (n = 65, mean 0.40 mmol/l; ±SD 0.14). Enteral glutamine provided only 28% of the recommendations. Glutamine was inversely correlated with length-of-stay (n = 98, r = -0.520, p < 0.001), ventilation (n = 98, r = -0.513, p < 0.001), lactate (n = 98, r = -0.41, p < 0.001) and CRP (n = 98, r = -0.51, p < 0.001). HSP70 was correlated with length-of-stay (n = 99, r = 0.30, p < 0.001), ventilation (n = 99, r = 0.31, p < 0.001), lactate (n = 99, r = 0.26, p < 0.001) and CRP (n = 99, r = 0.29, p < 0.001) and inflammatory mediators. There was no relationship between glutamine and HSP70 or inflammatory mediators. CONCLUSIONS: During acute illness HSP70/inflammatory mediators are significantly increased, and glutamine is significantly depleted. However, glutamine and HSP70 were not correlated. Enteral feeds only provided a small proportion of the ASPEN/ESPEN recommendations for glutamine.

Incidence of fatal food anaphylaxis in people with food allergy: a systematic review and meta-analysis.

BACKGROUND: Food allergy is a common cause of anaphylaxis, but the incidence of fatal food anaphylaxis is not known. The aim of this study was to estimate the incidence of fatal food anaphylaxis for people with food allergy and relate this to other mortality risks in the general population. METHODS: We undertook a systematic review and meta-analysis, using the generic inverse variance method. Two authors selected studies by consensus, independently extracted data and assessed the quality of included studies using the Newcastle-Ottawa assessment scale. We searched Medline, Embase, PsychInfo, CINAHL, Web of Science, LILACS or AMED, between January 1946 and September 2012, and recent conference abstracts. We included registries, databases or cohort studies which described the number of fatal food anaphylaxis cases in a defined population and time period and applied an assumed population prevalence rate of food allergy. RESULTS: We included data from 13 studies describing 240 fatal food anaphylaxis episodes over an estimated 165 million food-allergic person-years. Study quality was mixed, and there was high heterogeneity between study results, possibly due to variation in food allergy prevalence and data collection methods. In food-allergic people, fatal food anaphylaxis has an incidence rate of 1.81 per million person-years (95%CI 0.94, 3.45; range 0.63, 6.68). In sensitivity analysis with different estimated food allergy prevalence, the incidence varied from 1.35 to 2.71 per million person-years. At age 0-19, the incidence rate is 3.25 (1.73, 6.10; range 0.94, 15.75; sensitivity analysis 1.18-6.13). The incidence of fatal food anaphylaxis in food-allergic people is lower than accidental death in the general European population. CONCLUSION: Fatal food anaphylaxis for a food-allergic person is rarer than accidental death in the general population.

ctDNA binding affinity and in vitro antitumor activity of three Keggin type polyoxotungestates.

The ctDNA-binding properties and in vitro antitumor activity of three water soluble Keggin type polyoxometalates (POMs): K6H[CoW11O39CpZr]·nH2O, K6H[CoW11O39CpTi·nH2O and K7H2[CoW11O39CpFe]·nH2O (abbreviated as CoWCpZr, CoWCpTi and CoWCpFe, respectively) were investigated using UV-Vis absorption spectroscopy, fluorescence spectrophotometry, cyclic voltammetry and MTT assay. The results of UV-Vis, fluorescence and cyclic voltammetry rule out intercalating binding mode and propose the groove or outside stacking binding of these POMs with ctDNA. The values of 1.30×10(4) M(-1), 1.15×10(4) M(-1) and 3.10×10(3) M(-1) were obtained for binding constant of CoWCpZr, CoWCpTi and CoWCpFe to ctDNA, respectively. The redox potential of POMs shift to more negative values in the presence of ctDNA which can be related to domination of electrostatic interaction in this system. The antitumor activity tests of these polyoxometalates (POMs) were carried out on two types of human cancer cells, MCF-7 and HEK-293 by MTT method. The results show the higher antitumor activity of CoWCpFe respect to two other that is related to its highest penetrating effectiveness for MCF-7 cells. Therefore, the antitumor activity of these POMs depends not only on their affinity to ctDNA but also strongly on their penetration ability to the cell membrane.

Electronic and magnetic structure of the Cr(001) surface.

Density functional theory (DFT) calculations are carried out to study the electronic and magnetic structure of the (001) surface of chromium. Our aim is to identify and characterize the most prominent electronic surface states and make the connection with the main experimental results. We show that a low dispersive minority spin surface state at the center of the surface Brillouin zone plays a crucial role. This surface state of Δ1 symmetry at 0.58 eV above the Fermi level exhibits a predominantly dz(2) as well as pz orbital character. Local density of states (LDOS) analysis in the vacuum above the surface shows that the sharp feature originating from this surface state persists far away above the surface because of the slow decay rate of the pz wavefunction. Finally, by artificially lowering the surface magnetic moment [Formula: see text] on the outermost surface layer we find excellent agreement with experiments for [Formula: see text]. In addition, we propose that some extra spin polarized scanning tunneling spectroscopy (SP-STS) experiments should be made at smaller tip-surface distances to reveal additional features originating from the majority spin dz(2) surface state.

Comparison of Agar Dilution, Broth Dilution, Cylinder Plate and Disk Diffusion Methods for Evaluation of Anti-leishmanial Drugs on Leishmania promastigotes.

BACKGROUND: Leishmaniases are a group of diseases caused by Leishmania parasites. Growing of drug unresponsiveness in leishmaniasis patients necessitates the development of new drugs and accordingly a suitable assay is needed for evaluation of any modalities. The aim of this study was to compare four drug assays methods, agar dilution, broth dilution, cylinder plate and disk diffusion, for evaluation of anti-leishmanial drugs on Leishmania promastigotes, using glucantime as a currently available drug for treatment of leishmaniasis. METHODS: For broth dilution method, different concentration of glucantime was added to the parasite culture (promastigotes of Leishmania), while in cylinder plate method wells were punched in agar gel and filled with different concentration of drug and zone of inhibition was measured in each well. In disk diffusion method, the parasites were cultivated on the surface of agar; filter paper disks were enriched with various concentration of glucantime and were placed on the surface of agar. In agar dilution method, various concentrations of drug were incorporated onto blood agar and the parasites were cultivated on the surface of the agar. RESULTS: A direct correlation was found between the drug concentration and size of inhibitory zones in cylinder plate and disk diffusion methods. These two drug assays methods provided much better performance in comparison with broth and agar dilution methods. CONCLUSION: Cylinder plate and disk diffusion methods seem to be acceptable methods for susceptibility testing of anti-leishmanial compounds on Leishmania promastigotes.

Involvement of dopaminergic and glutamatergic systems of the basolateral amygdala in amnesia induced by the stimulation of dorsal hippocampal cannabinoid receptors.

The present study intended to investigate the involvement of dopaminergic and glutamatergic systems of the basolateral amygdala in amnesia induced by the stimulation of dorsal hippocampal cannabinoid receptors in male Wistar rats. The animals were stereotaxically implanted with guide cannulas in the CA1 region of the dorsal hippocampus and basolateral amygdala (BLA), trained in a step-through type passive avoidance task, and tested 24 h after training to measure memory retrieval. Post-training intra-CA1 microinjection of the nonselective CB1/CB2 receptor agonist WIN55,212-2 (WIN) (0.1-0.5 µg/rat) dose-dependently induced amnesia. Post-training intra-BLA administration of the D1/D2 dopamine receptor agonist apomorphine (0.3 and 0.5 µg/rat) plus intra-CA1 administration of 0.1 µg/rat of WIN, which alone did not induce amnesia, inhibited memory formation. The inhibitory effect of 0.5 µg/rat of WIN (intra-CA1) on memory formation was significantly decreased by the D1 dopamine receptor antagonist SCH23390 (0.1-0.5 µg/rat, intra-BLA) or the D2 dopamine receptor antagonist sulpiride (0.02-0.5 µg/rat, intra-BLA) given 5 min before post-training intra-CA1 microinjection of WIN. It is important to note that single intra-BLA microinjection of the same doses of apomorphine, SCH23390 or sulpiride had no effect on memory retrieval in passive avoidance task. On the other hand, post-training co-administration of N-methyl-d-aspartate (NMDA; 0.03 and 0.05 µg/rat, intra-BLA) plus an ineffective dose of WIN (0.1 µg/rat, intra-CA1) induced amnesia. Furthermore, the inhibitory effect of 0.5 µg/rat of intra-CA1 microinjection of WIN on memory formation was significantly decreased by pre-treatment with intra-BLA microinjection of the NMDA receptor antagonist d-2-amino-5-phosphonopentanoic acid (d-AP5; 0.1 and 0.5 µg/rat, intra-BLA). Intra-BLA microinjection of the same doses of NMDA or d-AP5 by itself did not induce any response on memory retrieval. Taken together, these findings support the existence of a functional interaction between dorsal hippocampal and basolateral amygdaloid neural circuits during processing cannabinoid-induced amnesia.

Comparison of three methods for diagnosis of cutaneous leishmaniasis.

BACKGROUND: Leishmaniasis is one of the infectious parasitic diseases of highest incidence in the world. Cutaneous Leishmaniasis (CL) has long been reported in Shiraz, Southern Iran. There is a need to find a sensitive and specific method for treatment and control of the disease. METHODS: We have compared the sensitivity of the conventional methods microscopy and cultivation of lesion scrapes against PCR amplification of parasite kinetoplast DNA from these samples. The samples (n=219) were obtained from the patients clinically suspected of CL. The smears were stained with Giemsa for microscopy and cultured in Novy-Nicolle-McNeal (NNN) blood agar for promastigote growth. For PCR, the dry smears were scraped off the slides and DNA was extracted. RESULTS: The positive rates from 219 specimens were 76.71%, 50.68%, and 93.61% for microscopy, cultivation, and PCR, respectively. The highest correlation was found between PCR and microscopy method (P=0.014). In PCR assay, 95.61%, 3.9%, and 0.49% of the samples were identified as Leishmania major, L. tropica, and dermatropic L. infantum, respectively. CONCLUSION: The PCR method appears to be the most sensitive for the diagnosis of CL and is valuable for identifying the other species of Leishmania with confusing dermatropic signs.

The impact of enteral feeding protocols on nutritional support in critically ill children.

BACKGROUND: Studies have shown that feeding protocols may assist in achieving optimal nutritional care in critically ill children. The present study aimed to assess the impact of enteral feeding protocols on nutritional support practices through a continuous auditing process over a defined period. MATERIALS AND METHODS: A prospective audit on nutritional practice was initiated in 1994-1995 on all ventilated patients who were admitted for more than a complete 24-h period in the paediatric intensive care unit. The audit was repeated 1997-1998, 2001 and 2005. The collection of data on outcomes included the time taken to initiate nutritional support, the proportion of patients fed via the enteral versus parenteral route, and the proportion of children reaching 50% and 70% of the estimated average requirement (EAR) by day 3. Feeding algorithms and protocols were introduced after each audit with a view to improving practices. RESULTS: Over the study period, time taken to initiate nutrition support was reduced from 15 h (1994-1995), 8 h (1997-1998), 5.5 h (2001) to 4.5 h (2005). The proportion of patients on parenteral feeds was reduced from 11% (1994-1995) to 4% (2005). An increase was also documented in the percentage of patients receiving a daily energy provision of 50% and 70% of the EAR by day 3 after the initiation of nutritional support (6% in 1994-1995 to 21% in 2005 for 70% of EAR). CONCLUSION: The present study demonstrates that feeding protocols improve nutritional practices in a paediatric intensive care unit. However, protocol introduction needs to be monitored regularly through audit.

Influence of a multidisciplinary paediatric allergy clinic on parental knowledge and rate of subsequent allergic reactions.

BACKGROUND: Studies have demonstrated that families of children with food allergy have significant deficiencies in their knowledge of how to avoid allergen exposure and how to manage allergic reactions. This study aims to assess the impact of a multidisciplinary paediatric allergy clinic consultation on parental knowledge of food allergy and to determine the rate of subsequent allergic reactions. METHODS: Sixty-two subjects (<17 years) referred with food allergy were prospectively enrolled. Parental knowledge was assessed by questionnaire and EpiPen trainer. Families saw a paediatric allergist, clinical nurse specialist and dietician. Knowledge was reassessed after 3 months and rate of allergic reactions after 1 year. RESULTS: After one visit to the paediatric allergy clinic, there was a significant improvement in parental knowledge of allergen avoidance (26.9%, P < 0.001), managing allergic reactions (185.4%, P < 0.0001) and EpiPen usage (83.3%, P < 0.001). Additionally, there was a significant reduction in allergic reactions (P < 0.001). Children with egg, milk or multiple food allergies were more likely to suffer subsequent reactions. CONCLUSIONS: A single visit to a multidisciplinary allergy clinic considerably improves families' abilities to manage allergic reactions to foods with an accompanying reduction in allergic reactions. Young children with egg, milk or multiple food allergies were at greatest risk of further reactions.

Does the use of a specialised paediatric retrieval service result in the loss of vital stabilisation skills among referring hospital staff?

AIMS: To compare the proportion of airway and vascular access procedures performed by referring hospital staff on critically ill children in two discrete time periods, before and after widespread use of a specialised paediatric retrieval service. METHODS: Transport data were obtained from retrieval logs of all children for whom a paediatric retrieval team was launched in each of two time periods (October 1993 to September 1994; and October 2000 to September 2001). RESULTS: The overall intubation rate was similar in the first and second time periods (83.9% v 79.1%). However, 31/51 (61%) retrieved children were intubated by referring hospital staff in 1993-94, compared to 227/269 (84%) in 2000-01. Referring hospital staff gained central venous access in 11% v 18% and arterial access in 22% v 19% of retrieved children in the first and second time periods respectively. This was in spite of a significant reduction in the proportion of children on whom these procedures were performed. CONCLUSION: Referring hospital staff are performing a greater proportion of initial airway and vascular access procedures undertaken in the stabilisation of sick children retrieved by a specialised paediatric retrieval team. The provision of this service has not resulted in the loss of vital skills at the local hospital.

A comparison of three scoring systems for mortality risk among retrieved intensive care patients.

AIMS: To assess the impact of two paediatric intensive care unit retrieval teams on the performance of three mortality risk scoring systems: pre-ICU PRISM, PIM, and PRISM II. METHODS: A total of 928 critically ill children retrieved for intensive care from district general hospitals in the south east of England (crude mortality 7.8%) were studied. RESULTS: Risk stratification was similar between the two retrieval teams for scores utilising data primarily prior to ICU admission (pre-ICU PRISM, PIM), despite differences in case mix. The fewer variables required for calculation of PIM resulted in complete data collection in 88% of patients, compared to pre-ICU PRISM (24%) and PRISM II (60%). Overall, all scoring systems discriminated well between survival and non-survival (area under receiver operating characteristic curve 0.83-0.87), with no differences between the two hospitals. There was a tendency towards better discrimination in all scores for children compared to infants and neonates, and a poor discrimination for respiratory disease using pre-ICU PRISM and PRISM II but not PIM. All showed suboptimal calibration, primarily as a consequence of mortality over prediction among the medium (10-30%) mortality risk bands. CONCLUSIONS: PIM appears to offer advantages over the other two scores in terms of being less affected by the retrieval process and easier to collect. Recalibration of all scoring systems is needed.

Noninvasive measurement of cardiac output in critically ill children.

This study was performed to evaluate the hemodynamic status of children admitted to the intensive care unit, using suprasternal and transesophageal Doppler ultrasound, and to establish a suitable noninvasive technique to monitor trends in cardiac output in critically ill children. Twenty children were studied over a period of 6 months. The median age was 32.5 months and weight 14.5 kg. Minute distance (MD), which is a linear cardiac output parameter, was assessed. Seven simultaneous pairs of measurements of MD were made using transesophageal Doppler (TED) and suprasternal Doppler (SSD) by the same operator. Following a fluid challenge, seven repeat pairs of measurements were made. The mean percentage changes for MD by TED and SSD were 21.84 (SD 9.97) and 5.75 (SD 7.32). The average coefficients of variation for measurements of MD by TED and SSD were 2.34% and 15.98%, respectively. The mean difference in percentage change between MD, measured by TED and SSD, was 27.59 with a 95% confidence interval and wide limits of agreement. The repeatability of TED measurements was good, but the measurements by SSD were wide and erratic with poor reproducibility. Our study shows that TED is easy to use, reliable, and very useful for monitoring hemodynamic changes in critically ill children.

Reduction in case fatality rate from meningococcal disease associated with improved healthcare delivery.

BACKGROUND AND AIMS: The case fatality rate from meningococcal disease (MD) has remained relatively unchanged in the post antibiotic era, with 20-50% of patients who develop shock still dying. In 1992 a new paediatric intensive care unit (PICU) specialising in MD was opened. Educational information was disseminated to local hospitals, and a specialist transport service was established which delivered mobile intensive care. The influence of these changes on mortality of children with MD was investigated. METHODS: A total of 331 consecutive children with meningococcal disease admitted to the PICU between 1992 and 1997 were studied. Severity of the disease on admission was assessed using the paediatric risk of mortality (PRISM) score. Logistic regression analysis was used to correct for clinical severity, age, and sex; death was the outcome, and year of admission, a temporal trend variable, was the primary exposure. RESULTS: The case fatality rate fell year on year (from 23% in 1992/93 to 2% in 1997) despite disease severity remaining largely unchanged. After adjustment for age, sex, and disease severity, the overall estimate for improvement in the odds of death was 59% per year (odds ratio for the yearly trend 0.41). CONCLUSIONS: A significant improvement in outcome for children admitted with MD to a PICU has occurred in association with improvements in initial management of patients with MD at referring hospitals, use of a mobile intensive care service, and centralisation of care in a specialist unit.

A myocardial cytotoxic process is involved in the cardiac dysfunction of meningococcal septic shock.

OBJECTIVE: Myocardial dysfunction is a characteristic component of meningococcal septic shock and contributes to the persisting high mortality from the disease. Specific treatment of the myocardial failure has been hampered by the lack of understanding of its pathophysiology. We were interested to determine whether myocardial cell death was occurring in the presence of meningococcal septicemia and whether it correlated with the degree of left ventricular dysfunction and disease severity. We therefore investigated the release of cardiac troponin I (cTnI), a sensitive and specific marker of myocardial cell death, and related this to the severity of disease and cardiac dysfunction. DESIGN: Prospective study SETTING: Pediatric intensive care unit SUBJECTS: Patients admitted to the pediatric intensive care unit with a diagnosis of meningococcal septicemia. INTERVENTIONS: Serum concentrations of cTnI were determined at admission to intensive care in 101 children with meningococcal septicemia and serially in 37 children. Changes in cTnI were related to disease severity as measured by the Pediatric Risk of Mortality score and two markers of cardiac dysfunction. MEASUREMENTS AND MAIN RESULTS: Serum concentrations of cTnI were elevated above the range for healthy children in 24% of children with meningococcal septicemia at admission and in 62% of patients within 48 hrs. The peak concentrations occurred between 12 and 36 hrs after admission. There were significant correlations between cTnI levels and disease severity and between cTnI levels and the degree of myocardial depression measured by quantitative transthoracic echocardiography and peak inotrope requirements. CONCLUSIONS: The elevated serum concentrations of cTnI indicate that myocardial cell death is occurring in meningococcal septicemia. The relationship between cTnI and markers of myocardial function suggest that the cell death may have a role in the pathogenesis of myocardial dysfunction in meningococcal septicemia. Elucidation of the mechanism responsible for myocardial injury may lead to the development of therapeutic interventions to prevent or limit this cardiac damage.

Efficacy of chest CT in a pediatric ICU: a prospective study.

STUDY OBJECTIVES: (1) To determine whether chest CT provides additional information compared with chest radiography regarding the nature of intrathoracic disease in critically ill children, (2) to determine whether such information alters clinical management, (3) to assess the role of a low-dose high-resolution CT (HRCT) protocol in pediatric ICU (PICU) patients. DESIGN: Prospective study. SETTING: Specialized PICU in a teaching hospital serving London and the south of England. PATIENTS: Twenty children (age range, 3 weeks to 12 years; median, 11 months) underwent chest CT during a 33-month period. Inclusion criteria were (1) inconclusive diagnosis from chest radiograph (CXR) or (2) CXR appearances inconsistent with high oxygenation or ventilatory requirements (PaO(2) to fraction of inspired oxygen ratio < 30 or mean airway pressure > 15 cm H(2)O). INTERVENTIONS: Low-dose HRCT scans (50 mA, 2-mm slice thickness at intervals of 10 or 15 mm) were performed on 12 patients, and helical CT (50 to 250 mA; pitch, 1 to 1.5) performed on 8 patients. MEASUREMENTS AND RESULTS: CT provided additional information regarding the nature of intrathoracic disease in 17 of 20 patients (85%) and resulted in changes to subsequent clinical management in 12 of 20 patients (60%). CONCLUSIONS: Chest CT can add to the accuracy of intrathoracic diagnosis provided by the CXR and may directly influence the acute management of critically ill children. The CT protocol should be tailored to the clinical and radiologic question posed for each individual patient. Noncontiguous HRCT can often provide accurate assessment of pulmonary parenchymal and pleural disease at a reduced radiation dose compared with helical CT.