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Najafi N, Hofer G, Gattinger P, Smiljkovic D, Blatt K, Selb R, Stoecklinger A, Keller W, Valent P, Niederberger V, Thalhamer J, Valenta R, Flicker S. Fusion proteins consisting of Bet v 1 and Phl p 5 form IgE-reactive aggregates with reduced allergenic activity. Sci Rep 2019; 9:4006. [PMID: 30850635 PMCID: PMC6408504 DOI: 10.1038/s41598-019-39798-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 01/28/2019] [Indexed: 11/16/2022] Open
Abstract
The cross-linking of effector cell-bound IgE antibodies by allergens induces the release of inflammatory mediators which are responsible for the symptoms of allergy. We demonstrate that a recombinant hybrid molecule consisting of the major birch (Bet v 1) and grass (Phl p 5) pollen allergen exhibited reduced allergenic activity as compared to equimolar mixes of the isolated allergens in basophil activation experiments. The reduced allergenic activity of the hybrid was not due to reduced IgE reactivity as demonstrated by IgE binding experiments using sera from allergic patients. Physicochemical characterization of the hybrid by size exclusion chromatography, dynamic light scattering, negative-stain electron microscopy and circular dichroism showed that the hybrid occurred as folded aggregate whereas the isolated allergens were folded monomeric proteins. IgG antibodies raised in rabbits against epitopes of Bet v 1 and Phl p 5 showed reduced reactivity with the hybrid compared to the monomeric allergens. Our results thus demonstrate that aggregation can induce changes in the conformation of allergens and lead to the reduction of allergenic activity. This is a new mechanism for reducing the allergenic activity of allergens which may be important for modifying allergens to exhibit reduced side effects when used for allergen-specific immunotherapy.
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Affiliation(s)
- N Najafi
- Division of Immunopathology, Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - G Hofer
- Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, Graz, Austria
| | - P Gattinger
- Division of Immunopathology, Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - D Smiljkovic
- Department of Internal Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna, Austria
| | - K Blatt
- Department of Internal Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna, Austria
| | - R Selb
- Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria
| | - A Stoecklinger
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - W Keller
- Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, Graz, Austria
| | - P Valent
- Department of Internal Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna, Austria
| | - V Niederberger
- Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria
| | - J Thalhamer
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - R Valenta
- Division of Immunopathology, Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.,NRC Institute of Immunology FMBA of Russia, Moscow, Russia.,Laboratory for Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, Moscow, Russia
| | - S Flicker
- Division of Immunopathology, Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
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Najafi N, Van de Velde A, Poelaert J. Alterations in haemodynamic parameters during procedural sedation and analgesia in children: Is ketamine really to blame? Hum Exp Toxicol 2018; 37:102-103. [DOI: 10.1177/0960327116689718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- N Najafi
- Department of Anaesthesiology and Perioperative Medicine, Vrije Universiteit Brussel–Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - A Van de Velde
- Department of Anaesthesiology and Perioperative Medicine, Vrije Universiteit Brussel–Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - J Poelaert
- Department of Anaesthesiology and Perioperative Medicine, Vrije Universiteit Brussel–Universitair Ziekenhuis Brussel, Brussels, Belgium
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Sakhdari SH, JafariNaini AH, kharazi MH, Najafi N. Evaluating the Correlation between the Body Mass Index (BMI) and Dental Age in 6 to 13-Yyear-Old Children. J Res Dentomaxillofac Sci 2016. [DOI: 10.29252/jrdms.1.4.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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Najafi N, Veyckemans F, Van de Velde A, Poelaert J. Usability of dexmedetomidine for deep sedation in infants and small children with respiratory morbidities. Acta Anaesthesiol Scand 2016; 60:865-73. [PMID: 26940080 DOI: 10.1111/aas.12715] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 01/17/2016] [Accepted: 01/26/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND Children with respiratory morbidities are at increased risk of developing adverse respiratory events while undergoing deep sedation. Dexmedetomidine possesses sedative properties with minimal respiratory depression. This report aimed to determine the usability of dexmedetomidine in children with significant respiratory morbidities who require deep sedation. METHODS Medical records of children with ASA classification III who had at least three characteristics of respiratory morbidities and who received dexmedetomidine sedation for magnetic resonance imaging (MRI) between January 2014 and May 2015 were retrospectively reviewed. Dexmedetomidine was administered as a bolus of 1 μg/kg over 10 min followed by 1 μg/kg/h infusion. If necessary, an additional bolus dose was given and the infusion rate was increased to 2 μg/kg/h. Respiratory morbidities, haemodynamic parameters, total dexmedetomidine dose, adverse cardiorespiratory events and sedation characteristics were analysed. RESULTS Nineteen out of 642 children who underwent MRI were eligible for evaluation. Seventeen children (89%) had at least four characteristics of respiratory morbidities. The median [IQR] age was 9 months [3.5-14]. All patients completed MRI scans while breathing spontaneously via the native airway. No episodes of adverse respiratory events or haemodynamic instability were observed. Children who were administered a lower dexmedetomidine dose and had a shorter sedation time were more likely to be younger than 1 year of age. CONCLUSION These data demonstrate that dexmedetomidine deep sedation was well-tolerated in children with significant respiratory morbidities. Moreover, children younger than 1 year of age were administered lower dexmedetomidine dose than children older than 1 year of age for the same sedation level. TRIAL REGISTRATION ClinicalTrials.gov identifier NCT02555605.
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Affiliation(s)
- N. Najafi
- Department of Anaesthesiology and Perioperative Medicine; Universitair Ziekenhuis Brussel (UZBrussel); Vrije Universiteit Brussel (VUB); Brussels Belgium
| | - F. Veyckemans
- Department of Anaesthesiology; Cliniques universitaires Saint Luc (UCL); Brussels Belgium
| | - A. Van de Velde
- Department of Anaesthesiology and Perioperative Medicine; Universitair Ziekenhuis Brussel (UZBrussel); Vrije Universiteit Brussel (VUB); Brussels Belgium
| | - J. Poelaert
- Department of Anaesthesiology and Perioperative Medicine; Universitair Ziekenhuis Brussel (UZBrussel); Vrije Universiteit Brussel (VUB); Brussels Belgium
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Levin M, Rotthus S, Wendel S, Najafi N, Källström E, Focke-Tejkl M, Valenta R, Flicker S, Ohlin M. Multiple independent IgE epitopes on the highly allergenic grass pollen allergen Phl p 5. Clin Exp Allergy 2015; 44:1409-19. [PMID: 25262820 PMCID: PMC4278554 DOI: 10.1111/cea.12423] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Revised: 07/06/2014] [Accepted: 08/15/2014] [Indexed: 11/30/2022]
Abstract
Background Group 5 allergens are small proteins that consist of two domains. They belong to the most potent respiratory allergens. Objective To determine the binding sites and to study allergic patients' IgE recognition of the group 5 allergen (Phl p 5) from timothy grass pollen using human monoclonal IgE antibodies that have been isolated from grass pollen allergic patients. Methods Using recombinant isoallergens, fragments, mutants and synthetic peptides of Phl p 5, as well as peptide-specific antibodies, the interaction of recombinant human monoclonal IgE and Phl p 5 was studied using direct binding and blocking assays. Cross-reactivity of monoclonal IgE with group 5 allergens in several grasses was studied and inhibition experiments with patients' polyclonal IgE were performed. Results Monoclonal human IgE showed extensive cross-reactivity with group 5 allergens in several grasses. Despite its small size of 29 kDa, four independent epitope clusters on isoallergen Phl p 5.0101, two in each domain, were recognized by human IgE. Isoallergen Phl p 5.0201 carried two of these epitopes. Inhibition studies with allergic patients' polyclonal IgE suggest the presence of additional IgE epitopes on Phl p 5. Conclusions & Clinical Relevance Our results reveal the presence of a large number of independent IgE epitopes on the Phl p 5 allergen explaining the high allergenic activity of this protein and its ability to induce severe allergic symptoms. High-density IgE recognition may be a general feature of many potent allergens and form a basis for the development of improved diagnostic and therapeutic procedures in allergic disease.
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Affiliation(s)
- M Levin
- Department of Immunotechnology, Lund University, Lund, Sweden
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Hajiabdolbaghi M, Rasoulinejad M, Davoudi AR, Alikhani A, Najafi N. Application of peripheral blood Mycobacterium tuberculosis PCR for diagnosis of tuberculosis patients. Eur Rev Med Pharmacol Sci 2014; 18:185-189. [PMID: 24488906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
BACKGROUND Mycobacterium tuberculosis (MTB) infection is a global health problem. Failure to accurately identify cases of active MTB has serious effects on both patients and the community. Acid-fast bacilli (AFB) smear has poor sensitivity and culture methods have a delay ranging from 1 to 8 weeks for diagnosis. Nucleic acid amplification assays may be suitable candidates for this purpose. PATIENTS AND METHODS In a prospective study, we evaluated Mycobacterium tuberculosis DNA in peripheral blood samples with PCR technique in 190 patients with pulmonary and extra pulmonary tuberculosis whom were admitted to Tehran Imam Khomeini hospitals during 2006-2010. Three ml citrated blood samples were obtained from cases. DNA extraction was performed by QIAGEN commercial kit and PCR performed with IS1081 Primer. RESULTS Fifty six cases had extra-pulmonary tuberculosis and 134 were pulmonary. Overall sensitivity and specificity of the PCR assay was 41.1% and 95.5%, respectively. CONCLUSIONS MTB-PCR assay on PBMC using IS1081 primer has a low sensitivity and now can not use as a single or alternative diagnostic test for tuberculosis. However, with regard to its high specificity can use for help diagnosing of TB in cases have no enough sputum (or other specimens) to examination for acid-fast bacilli (AFB) smear and culture.
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Affiliation(s)
- M Hajiabdolbaghi
- Department of Infectious Diseases, Tehran University of Medical Sciences, Tehran, Iran.
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Najafi N, Heuzey M, Carreau P. Crystallization behavior and morphology of polylactide and PLA/clay nanocomposites in the presence of chain extenders. POLYM ENG SCI 2012. [DOI: 10.1002/pen.23355] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Najafi N, Veyckemans F, Berghmans J, De Groote F, De Villé A, Huys J, Lauweryns J, Loveniers B, Pirotte T, Roofthooft E, Veeckman L, Verhaeghen T, Vermeulen PM, Vermeylen K. Belgian recommendations on perioperative maintenance fluid management of surgical pediatric population. Acta Anaesthesiol Belg 2012; 63:101-109. [PMID: 23397661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The European recommendations on perioperative maintenance fluids in children have recently been adapted from hypotonic to isotonic electrolyte solutions with lower glucose concentrations. In Belgium, however, the commercially approved solutions do not match with these recommendations and there is neither consensus nor mandate about the composition and volume of perioperative maintenance fluids in children undergoing surgery despite the continuing controversy in literature. This paper highlights the significant challenges and shortcomings while prescribing fluid therapy for pediatric surgical patients in Belgium. It is sensible to the authors to address these issues with national guidance through an organization such as The Belgian Association for Paediatric Anaesthesiology, and to propose Belgian recommendations on perioperative fluid management in surgical children, with the intention of improving the quality of care in this population.
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Affiliation(s)
- N Najafi
- Dept of Paediatric Intensive Care Medicine, UZ Brussel, Vrije Universiteit Brussel (VUB), Brussels, Belgium.
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Najafi N, Hosseini R, Ahmadi AR. Impact of gamma rays on the Phaffia rhodozyma genome revealed by RAPD-PCR. Iran J Microbiol 2011; 3:216-21. [PMID: 22530091 PMCID: PMC3330186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND AND OBJECTIVES Phaffia rhodozyma is a red yeast which produces astaxanthin as the major carotenoid pigment. Astaxanthin is thought to reduce the incidence of cancer and degenerative diseases in man. It also enhances the immune response and acts as a free-radical quencher, a precursor of vitamin A, or a pigment involved in the visual attraction of animals as mating partners. The impact of gamma irradiation was studied on the Phaffia rhodozyma genome. MATERIALS AND METHODS Ten mutant strains, designated Gam1-Gam10, were obtained using gamma irradiation. Ten decamer random amplified polymorphic DNA (RAPD) primers were employed to assess genetic changes. RESULTS Nine primers revealed scorable polymorphisms and a total of 95 band positions were scored; amongst which 38 bands (37.5%) were polymorphic. Primer F with 3 bands and primer J20 with 13 bands produced the lowest and the highest number of bands, respectively. Primer A16 produced the highest number of polymorphic bands (70% polymorphism) and primer F showed the lowest number of polymorphic bands (0% polymorphism). Genetic distances were calculated using Jaccard's coefficient and the UPGMA method. A dendrogram was created using SPSS (version 11.5) and the strains were clustered into four groups. CONCLUSION RAPD markers could distinguish between the parental and the mutant strains of P. rhodozyma. RAPD technique showed that some changes had occurred in the genome of the mutated strains. This technique demonstrated the capability to differentiate between the parental and the mutant strains.
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Affiliation(s)
- N Najafi
- Women Research Centre, Biomedical Department, Alzahra University, Tehran, Iran,Agricultural Biotechnology Department, Faculty of Engineering, Imam Khomeini International University, Qazvin, Iran
| | - Ramin Hosseini
- Women Research Centre, Biomedical Department, Alzahra University, Tehran, Iran
| | - AR Ahmadi
- Women Research Centre, Biomedical Department, Alzahra University, Tehran, Iran, Corresponding author: Ali Reza Ahmadi, Ph.D Address: Women Research Centre, Biomedical Department, Alzahra University, Tehran, Iran. Tel: +98-21-85692803 Fax: +98-21-88049809. E-mail:
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Ahishakiye D, Najafi N, Van de Velde A, Poelaert J. A randomized controlled trial to evaluate the incidence of emergence agitation in children: A comparison of intravenous versus inhalational anesthesia. Eur J Anaesthesiol 2011. [DOI: 10.1097/00003643-201106001-00478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Mowlavi G, Naddaf S, Rezaeian M, Najafi N, Lucio-Forster A, Bowman D. Apparent pseudoparasitism of the alimentary canal of a 5-year-old child by the millipedeBrachyiulus lusitanus(Diplopoda: Julidae). Parasite 2009; 16:161-3. [DOI: 10.1051/parasite/2009162161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Ghasemian R, Najafi N. Knowledge and Performance Toward Universal Precautions Among Nurses in University-Affiliated Hospitals of Mazandaran, Iran. Int J Infect Dis 2008. [DOI: 10.1016/j.ijid.2008.05.987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Ghasemian R, Najafi N. General Practitioners and Medical Student's Knowledge and Perspectives Regarding Influenza (Treatment and Prevention). Int J Infect Dis 2008. [DOI: 10.1016/j.ijid.2008.05.817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Abstract
Although asthma usually begins in childhood, limited information is available as to the inflammatory reaction of asthmatic children compared to adults and the influence of age. We investigated the cytology of bronchoalveolar lavage fluid (BALF) in 39 newly diagnosed wheezy children (minimum of 3 wheezing episodes during last 6 months): 21 allergic and 18 nonallergic subjects. None had received antiinflammatory treatment. Bronchoalveolar lavage (BAL) was performed, instilling 0.5 ml.kg(-1) body weight of warmed saline in 4 successive fractions. The first 2 aliquots (BALF 1) were pooled for microbiology and cytology, and the last 2 (BALF 2) for cytology only. Recovery correlated inversely with age, the most significant being for BALF 2 (r = -0.52, P = 0.001). Children under 2 years of age had larger amounts of ciliated columnar and goblet cells (P = 0.0074). Other cell types did not show age dependency. Differential cytology was characterized by a high number of creola bodies, bronchial epithelial cells (M = 68 x 10(3).ml(-1), R = 5-349), and neutrophils (M = 92 x 10(3).ml(-1), R = 0-1,257). Eosinophils were the only cells distinguishing allergic from nonallergic subjects (P = 0.003). The 16 children with positive microbiology had more neutrophils than the noninfected (P = 0.008), the latter still having more neutrophils than found in adults. These data suggest a limited age dependency in BALF cytology. Differential cytology in BALF might be helpful in differentiating asthma in children. Neutrophil inflammation might be more important than in adults.
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Affiliation(s)
- N Najafi
- Department of Pediatrics, Pediatric Respiratory Medicine and Cystic Fibrosis Clinic, Academic Hospital-Brussels Free University (VUB), Brussels, Belgium
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Sparks D, Smith R, Straayer M, Cripe J, Schneider R, Chimbayo A, Anasari S, Najafi N. Measurement of density and chemical concentration using a microfluidic chip. Lab Chip 2003; 3:19-21. [PMID: 15100800 DOI: 10.1039/b211429a] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A new microfluidic product for measuring fluid density, specific gravity and chemical concentration has been developed. At the core of this lab-on-a-chip sensor is a vacuum-sealed resonating silicon microtube. Measurements can be made with under a microliter of sample fluid, which is over 1000x less than is conventionally required. Since the product is MEMS-based the overall system size is a fraction of conventional density meters and it weighs much less than the traditional desk-top, temperature controlled, density meters. The syringe or pipette loaded system includes a dynamic temperature control system that operates between 0 degree C and 90 degree C with an accuracy of less than 0.01 degree C. Density measurement accuracies of 4 to 5 digits have been observed with aqueous solutions. Measurement examples and applications will be discussed.
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Affiliation(s)
- D Sparks
- Integrated Sensing Systems Inc, 391 Airport Industrial Dr, Ypsilanti, MI 48198, USA.
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Ramet J, Najafi N, Benatar A. An Update of Childhood Meningococcal Sepsis. Intensive Care Med 2003. [DOI: 10.1007/978-1-4757-5548-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Najafi N, Philip R, Goldman A. Crit Care 2002; 6:P22. [DOI: 10.1186/cc1685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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