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Biomedical subjects

R Cremer

Publications and source records attributed to R Cremer.

At least 19 recordsLinked to original sources

[Non-invasive ventilation in infants with severe infection presumably due to respiratory syncytial virus: feasibility and failure criteria].

UNLABELLED: Beneficial effect of continuous positive airway pressure (CPAP) during non invasive ventilation (NIV) has been reported in infants with respiratory syncytial virus (RSV) infection, but no study has analyzed the predictors of its failure. OBJECTIVE: To evaluate the feasibility of NIV and to determine NIV failure criteria. POPULATION AND METHODS: All infants hospitalized in one PICU with presumed RSV infection between 2002 and 2006 were prospectively included. When respiratory support was needed, NIV was first started according to a pre-established protocol. RESULTS: One hundred and one infants, 43 females, 58 males, median age 49 days (range: 10-334), median weight 3.9 kg (range: 2,4-12) were included. RSV infection was confirmed in 84/101. Sixty-seven infants were transported by the paediatric medical transport system, 27 with NIV and 15 with invasive ventilation (IV). Fifteen infants were in IV at admission, 69 received NIV during their PICU stay (12 secondarily requiring IV) and 17 were never ventilated. A significant decrease in PCO2 with increase in pH was observed within 2 hours of NIV. Parameters associated with NIV failure were apneas, high values of admission PCO2 and H24 PRISM score. The 17 non-ventilated infants were older and had a lower severity score than those who were ventilated. CONCLUSION: In infants with RSV and needing respiratory support, NIV represented the sole method of respiratory support in 68% of cases. NIV failure criteria were apneas, high values of admission PCO2 and H24 PRISM score.

Child↗

[Withholding or withdrawing life saving treatment in pediatric intensive care unit: GFRUP guidelines].

Several recent French studies have revealed that 40% of death in pediatric intensive care units are associated with withdrawal or limitation of life saving treatments. Because such decisions are common, the Groupe francophone de réanimation et urgences pédiatriques (GFRUP) has decided to publish recommendations in order to help paediatricians dealing with those difficult issues and to improve their decisions. In a first part of the document the ethical principles that imply those guidelines are recalled, followed by definitions of the terms currently employed. The second part contains guidelines regarding decision making process, the way it is applied and organisation of relatives as well as paramedical and medical staff support when the death of a child occurs.

Child↗

Admission plasma vasopressin levels in children with meningococcal septic shock.

OBJECTIVE: Vasopressin (AVP) response has been reported to be inappropriately low in adult established septic shock. We studied admission AVP levels in children with meningococcal septic shock (MSS). PATIENTS AND METHODS: All children with meningococcal infection admitted to our PICU between May 2001 and August 2002 were classified as MSS (persistent hypotension despite fluid therapy, with perfusion abnormalities and the need for vasoactive drug infusion for at least 24 h or until death), or meningococal infection without shock (fever and purpura, with or without meningitis). Blood samples were collected at admission and AVP levels were subsequently determined using Nichols Institute Diagnostics vasopressin assay. Eighteen of 19 children with MSS (7 deaths) and 15 without shock (no death) were included. RESULTS: In children with MSS median admission AVP level was 41.6 pg/ml (1.4-498.9) and in those without 3.3 pg/ml (1.6-63.8). In children with MSS the AVP level was not correlated with duration of shock and fluid expansion prior to AVP sampling, or with age-adjusted blood pressure and natremia at the time of blood sampling. AVP levels were higher in nonsurvivors, but not significantly so. Only one nonsurvivor had an admission AVP level below 30 pg/ml. CONCLUSIONS: In our children with established MSS who died the admission AVP level Delta were not inappropriately low. Further studies including serial AVP level assessments are needed before concluding that AVP administration is of little interest in children with MSS.

Child, Preschool↗

Plastic bronchitis mimicking foreign body aspiration that needs a specific diagnostic procedure.

OBJECTIVE: To report two children admitted to our emergency department with respiratory failure, one for status asthmaticus with pneumomediastinum and requiring mechanical ventilation and the other for high suspicion of foreign body aspiration. INTERVENTIONS: Bronchoscopy revealed obstructive plugs and permitted their extraction and their identification as bronchial casts after the immersion in normal saline. Allergy was suspected in the first one, and Hemophilus influenzae infection was present in the second. The outcome was favorable. CONCLUSIONS: Plastic bronchitis is an infrequent cause of acute life-threatening respiratory failure that can mimic foreign body aspiration or status asthmaticus. Bronchoscopic extraction must be performed urgently in the case of severe obstruction. This entity is probably underestimated as the casts with their specific ramifications are difficult to recognize. We recommend the immersion in normal saline of all plugs discovered in children with predisposing diseases mainly represented by infections, allergy, acute chest syndrome, and congenital cardiopathies.

Acute Disease↗

Molecular cloning, purification, and IgE-binding of a recombinant class I chitinase from Hevea brasiliensis leaves (rHev b 11.0102).

BACKGROUND: Class I chitinase in natural rubber latex (NRL) has been assumed to be an important allergen, especially concerning its cross-reactivity with fruits like avocado and banana. OBJECTIVES: The present study aimed to produce a recombinant latex class I chitinase from Hevea brasiliensis leaves and to study its immunoglobulin (Ig)E-binding reactivity. METHODS: A class I chitinase-specific complementary DNA from H. brasiliensis leaves was synthesized, subcloned, sequenced and overexpressed in fusion with the maltose-binding protein (MBP) in Escherichia coli. The IgE-binding reactivity of this protein was studied by the Pharmacia CAP System and by immunoblot experiments using sera from latex-allergic patients. RESULTS: The rHev b 11.0102 was found to have a length of 295 amino acid residues and contains an N-terminal hevein-like domain with a 56% homology to hevein. Analysis by the CAP method revealed the presence of rHev b 11.0102-specific IgE antibodies in 17 of 58 sera (29%) of IgE-mediated latex-allergic subjects tested. Immunoblot analysis of the MBP-rHev b 11.0102 fusion protein and the MBP carrier protein as a negative control confirmed the IgE-reactivity of rHev b 11.0102. CONCLUSION: Due to its IgE-reactivity rHev b 11.0102 represents an allergen of intermediate prevalence in NRL. Its property to cross-react with certain fruits makes it an important supplement in the diagnostic panel of recombinant NRL allergens.

Adolescent↗

In situ surface analysis of annealed Fe-1.5%Mn and Fe-0.6%Mn low alloy steels.

The oxidation of two binary alloys, Fe-1.5%Mn and Fe-0.6%Mn, was studied in terms of the annealing conditions and paying special attention to the selective oxidation of manganese. The crystallographic structure of the surfaces and their compositions were determined by RHEED and XPS by using in situ analytical devices attached to the annealing reactor to avoid surface contamination after the treatments. Additionally, ex situ investigations on the morphology and composition of the surfaces were performed by FEG-SEM, WDX, and GIXRD. The annealing processes were performed at 800 degrees C under N(2)-5%H(2) protective atmospheres at water vapor dew points between -10 and -30 degrees C. The oxides formed were identified and the resulting surface structures resolved.

Journal Article↗

Influence of the composition of BCN films deposited by reactive magnetron sputtering on their properties.

Compounds of the B--C--N system are very promising to produce superhard coatings with good tribological, chemical, and thermal properties. To investigate the influence of the composition of BCN films on their properties, films with five different compositions at nearly constant nitrogen content were deposited on silicon wafers by magnetron sputtering from hexagonal boron nitride and graphite targets operated in RF and DC mode, respectively. The compositions and binding states of the films were determined by XPS. The nitrogen content was found to be almost constant for all films at about a 40 at-%, whereas boron and carbon compositions ranged between 15-35 and 25-50 at-%, respectively. The electronic and bonding structure of the coatings were analyzed by REELS using three different electron beam energies to obtain information at different depths. An increase of the carbon content of the films resulted in a significant shift of the pi-pi* interband transition with respect to the energy loss corresponding to h-BN. The absence of the pi-pi* transition in the energy loss spectra acquired at a beam energy of 1900 eV indicates the existence of a very thin overlayer mostly sp(2) bonded and probably with a distorted hexagonal structure. The position of the bulk plasmon losses corresponded to the hexagonal phase for the overlayer and presented a shift of more than 1.5 eV to the higher energy loss direction for the spectra obtained at 1900 eV beam energy. This shift and the absence of the sp(2)-bond fingerprint induced the possibility of an underlying disordered structure with a majority of sp(3) bonds.

Journal Article↗

[Life-threatening Plasmodium falciparum parasitemia, in an infant returning from the tropics].

INTRODUCTION: Severe falciparum malaria is a polymorphous life-threatening disease. Hyperparasitemia is rare among non-immune children returning from tropical areas. CARE REPORT: We report a case of an infant returning from Ivory Coast who presented with fever, prostration and marked thrombocytopenia (22,000 platelets/mm(3)). Blood slide showed Plasmodium falciparum ring forms. Parasite density dramatically increased from 1.7% to 45%, and the child developed several features of severe malaria, according to WHO definition. CONCLUSION: In this non-immune infant, prostration and thrombopocytopenia seemed to be earlier predictors of severity than hyperparasitemia and other WHO criteria, which have not been yet validated in travelling children.

Animals↗

Reduction of latex sensitisation in spina bifida patients by a primary prophylaxis programme (five years experience).

Spina bifida patients represent a group with the highest risk for latex sensitisation and allergy with life-threatening symptoms mostly during surgery. At the end of 1995 we initiated a primary latex prophylaxis around and during surgery and anaesthesia of all spina bifida patients. The aim of our study was to investigate the prevalence of latex sensitisation in the spina bifida patients born during the five years after establishing latex prophylaxis in the Cologne Children's Hospital in December 1995. We investigated 34 serum samples of 27 spina bifida patients (mean age 2.4 years) for specific IgE antibodies against latex allergens (CAP system) and compared these patients born after 1995 with 38 spina bifida patients up to 5 years of age (mean 3.1 years) born before. In the prophylaxis group two of 27 patients (7 %), one of them with two operations outside the Children's Hospital, had low specific IgE against latex (</= 0.9 kU/l, 3 and 5 operations). The other patients in this group were not sensitised despite up to 8 operations (min. 1, mean 3.1). In contrast, before introducing the prophylaxis, 16 of 38 patients (42 %) were latex IgE-positive after multiple operations (min. 2, max. 11, mean 4.7) with values of specific IgE up to > 100 kU/l (mean 22.6 kU/l, min 0.4 kU/l). Sera of 22 patients remained negative for latex IgE (min. 1, max. 19, mean 4.3 operations). By primary latex prophylaxis during surgery, anaesthesia and in paediatric wards the prevalence of latex sensitisation can be significantly reduced even in the high risk group of spina bifida patients. Problems can arise by the need for surgery in hospitals not experienced in the treatment of spina bifida patients, where latex prophylaxis is neglected.

Case-Control Studies↗

[Treatment of meningococcal purpura fulminans].

In France, the incidence of meningococcal infections is increasing. The most severe presentation, called purpura fulminans, has a death rate of 20-25%; 5 to 20% of the survivors need skin grafts and/or amputations. Diagnosis of invasive meningococcal infection is very difficult when purpura and "toxic" appearance are absent: one should take into account parents' impression of their ill child. This diagnosis must be evoked in any child presenting with febrile purpura (like in the United Kingdom, parents should be encouraged to use the "tumbler test" to identify a vasculitic rash); a fulminant form is to be suspected in the presence of only one ecchymosis and signs of infection, remembering that recognition of shock is difficult in children. Recently, the Health Authority has recommended to administer a third generation cephalosporin promptly (before biological investigations) for any child with signs of infection and a necrotic or ecchymotic purpura (> 3 mm of diameter), and then to refer the patient to the hospital. By grouping the patients from 7 studies, it can be observed that preadmission antibiotic administration has a protective effect on mortality (odds ratio: 0.36; 95% confidence interval: 0.23-0.56); a negative effect was observed in only one of these series. Children with purpura fulminans should be referred to a paediatric intensive care unit. Management includes antibiotics, steroids, fluid resuscitation and catecholamines (be aware of hypoglycaemia, particularly in infants, and hypocalcaemia). Treatment of cutaneous necrosis and distal ischemia is difficult and still controversial: antithrombin, protein C, tissue plasminogen activator and vasodilator infusion have no proven efficacy. Cases must be rapidly notified to the Public Health Service who will institute chemoprophylaxis for close contacts. Given the predominance of serogroup B in France, we hope that an efficient vaccine will soon become available.

Anti-Bacterial Agents↗

Can generic scores (Pediatric Risk of Mortality and Pediatric Index of Mortality) replace specific scores in predicting the outcome of presumed meningococcal septic shock in children?

OBJECTIVE: To compare, in children with septic shock and purpura, the accuracy in predicting death of two specific scores (the MenOPP bedside clinical [MOC] score of Gedde Dahl and the score of Groupe Francophone de Réanimation Pédiatrique [GFRP]), the C-reactive protein (CRP) level, and the two pediatric generic scores (the Pediatric Risk of Mortality [PRISM] and Pediatric Index of Mortality [PIM] scores). DESIGN: Prospective, population-based study with analysis of previous comparative studies. SETTING: A 14-bed pediatric intensive care unit in a university hospital. PATIENTS: All children admitted consecutively to the pediatric intensive care unit with septic shock and purpura (n = 58, with 16 deaths [27.6%]) from January 1993 to May 2000. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The MOC and GFRP scores and the CRP level were prospectively determined at admission. The PRISM score was prospectively calculated within 24 hrs of admission or at the time of death, and the PIM score was calculated retrospectively between 1993 and 1997 and then prospectively from admission data. The nonparametric estimate of the area under the receiver operating characteristic curves (AUC) was calculated from the raw data using the Wilcoxon-Mann-Whitney two-sample statistic, and the standard error of the AUCs was calculated with DeLong's method. All the scores had an AUC >0.80, the PRISM probability of death having the best one (0.96 +/- 0.02). The PRISM value, which is easier to calculate, had an AUC of 0.95 +/- 0.02. The PRISM score performed significantly better than the PIM score (AUC, 0.83 +/- 0.06; p <.01) and the CRP level (AUC, 0.80 +/- 0.06; p <.01); however, there was no significant difference between the MOC (AUC, 0.91 +/- 0.04) and GFRP scores (AUC, 0.87 +/- 0.05). Analyzing literature and calculating AUCs from original data of previous studies, we observed that the superiority of the PRISM score had never been demonstrated in meningococcal diseases. CONCLUSIONS: The PRISM score performed better than the PIM score, and was not surpassed by specific scores. Thus, we propose its use for outcome prediction in children with septic shock and purpura. However, if the PRISM score is to be used as inclusion criterion for clinical trials, it should be evaluated within a few hours after admission.

Area Under Curve↗

PCR-based cloning, isolation, and IgE-binding properties of recombinant latex profilin (rHev b 8).

BACKGROUND: Profilin (Hev b 8) in natural rubber latex (NRL) has been assumed to be an important allergen. Since latex profilin has a molecular mass similar to two other latex allergens (Hev b 1 and Hev b 6.03) in the 14-kDa range, it is difficult to obtain sufficient amounts of purified native profilin for investigations and diagnostics. The present study aimed to produce recombinant latex profilin (rHev b 8) and study its IgE-binding reactivity. METHODS: A profilin-specific cDNA encoding the latex profilin from Hevea brasiliensis leaves was synthesized and subcloned, and the rHev b 8 was overexpressed in fusion with the maltose-binding protein (MBP) in E. coli. The IgE-binding reactivity of rHev b 8 was studied by immunoblotting, immunoblot inhibition experiments, and the Pharmacia CAP method, with 25 sera from health-care workers with latex allergy and 17 sera from latex-sensitive spina bifida patients. RESULTS: rHev b 8 was found to have 131 amino acids and a sequence identity of 75% with birch profilin (Bet v 2). Analysis by the CAP system revealed the presence of rHev b 8-specific IgE antibodies in two out of 17 sera from spina bifida patients and in five out of 25 sera (20%) from health-care workers. Two subjects of the latter group with rHev b 8-specific IgE showed negative results in the skin prick tests with tree-pollen extracts and had no IgE to rBet v 2, indicating the presence of IgE-binding epitopes on the Hev b 8-molecule which do not cross-react with birch profilin. Immunoblot inhibition assays using MBP-rHev b 8 as inhibitor confirmed the presence of latex profilin in the NRL extract. IgE binding to the native latex profilin could be completely inhibited by the MBP-rHev b 8. CONCLUSIONS: Latex profilin represents a minor allergen in NRL and may have IgE-binding epitopes different from Bet v 2.

Adult↗

Recombinant Hev b 1: large-scale production and immunological characterization.

BACKGROUND: Hev b 1 represents one of the most important allergens in Hevea brasiliensis latex. It is difficult to get an appropriate amount of native Hev b 1 (nHev b 1) for research purposes. OBJECTIVE: The aim of this study was to produce sufficient amounts of Hev b 1 by recombinant methods to prove its suitability for latex allergy diagnostics. METHODS: We isolated total RNA of Hevea brasiliensis leaves and synthesized cDNA by RT PCR. Recombinant Hev b 1 (rHev b 1) as well as three fragments (amino acid residues 29-137, 48-137, 78-137) were subcloned and expressed as fusion proteins with Maltose-binding protein (MBP) in Escherichia coli. The MBP-rHev b 1 fusion protein was examined by RAST with the CAP method, histamine release test and immunoblots with human sera from spina bifida patients as well as from health care workers with latex allergy and monoclonal antibodies. RESULTS: Histamine release test and immunoblots revealed the high allergenicity of the MBP-rHev b 1 construct. By the CAP method, 54 out of 58 serum samples (93%) from latex-sensitized spina bifida patients previously showing immunoglobulin (Ig) E to nHev b 1 exhibited IgE-binding to rHev b 1. Among 71 latex-allergic health care workers tested, 16 (22.5%) had IgE antibodies to rHev b 1. The analysis of the fusion proteins carrying rHev b 1 fragments revealed that the loss of the N-terminal 28 amino acid residues did not affect IgE-binding. In contrast, the lack of the first 47 amino acid residues led to decreased IgE-binding reactivity in two out of four sera tested, whereas the absence of the N-terminal 77 residues abolished IgE-binding in these two sera. CONCLUSION: The MBP-rHev b 1 fusion protein exhibits a corresponding IgE-binding reactivity to nHev b 1 and may therefore substitute natural Hev b 1 for both in vitro diagnostics and research purposes.

ATP-Binding Cassette Transporters↗