Publications by authors named "John S Sullivan"

37 Publications

Serological Immunity to Smallpox in New South Wales, Australia.

Viruses 2020 05 18;12(5). Epub 2020 May 18.

Biosecurity Program, Kirby Institute, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia.

The re-emergence of smallpox is an increasing and legitimate concern due to advances in synthetic biology. Vaccination programs against smallpox using the vaccinia virus vaccine ceased with the eradication of smallpox and, unlike many other countries, Australia did not use mass vaccinations. However, vaccinated migrants contribute to population immunity. Testing for vaccinia antibodies is not routinely performed in Australia, and few opportunities exist to estimate the level of residual population immunity against smallpox. Serological data on population immunity in Australia could inform management plans against a smallpox outbreak. Vaccinia antibodies were measured in 2003 in regular plasmapheresis donors at the Australian Red Cross Blood Service from New South Wales (NSW). The data were analysed to estimate the proportion of Australians in NSW with detectable serological immunity to vaccinia. The primary object of this study was to measure neutralising antibody titres against vaccinia virus. Titre levels in donor samples were determined by plaque reduction assay. To estimate current levels of immunity to smallpox infection, the decline in geometric mean titres (GMT) over time was projected using two values for the antibody levels estimated on the basis of different times since vaccination. The results of this study suggest that there is minimal residual immunity to the vaccinia virus in the Australian population. Although humoral immunity is protective against orthopoxvirus infections, cell-mediated immunity and immunological memory likely also play roles, which are not quantified by antibody levels. These data provide an immunological snapshot of the NSW population, which could inform emergency preparedness planning and outbreak control, especially concerning the stockpiling of vaccinia vaccine.
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http://dx.doi.org/10.3390/v12050554DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7291091PMC
May 2020

Possible clearance of transfusion-acquired /LTR-deleted attenuated HIV-1 infection by an elite controller with CCR5 Δ32 heterozygous and HLA-B57 genotype.

J Virus Erad 2019 Apr 1;5(2):73-83. Epub 2019 Apr 1.

Centre for Applied Medical Research, St Vincent's Hospital, Sydney, NSW, Australia.

Background: Subject C135 is one of the members of the Sydney Blood Bank Cohort, infected in 1981 through transfusion with attenuated /3' long terminal repeat (LTR)-deleted HIV-1, and has maintained undetectable plasma viral load and steady CD4 cell count, in the absence of therapy. Uniquely, C135 combines five factors separately associated with control of viraemia: /LTR-deleted HIV-1, HLA-B57, HLA-DR13, heterozygous CCR5 Δ32 genotype and vigorous p24-stimulated peripheral blood mononuclear cell (PBMC) proliferation. Therefore, we studied in detail viral burden and immunological responses in this individual.

Methods: PBMC and gut and lymph node biopsy samples were analysed for proviral HIV-1 DNA by real-time and nested PCRs, and /LTR alleles by nested PCR. HIV-specific antibodies were studied by Western blotting, and CD4+ and CD8+ T lymphocyte responses were measured by proliferation and cytokine production .

Results: PBMC samples from 1996, but not since, showed amplification of alleles with gross deletions. Infectious HIV-1 was never recovered. Proviral HIV-1 DNA was not detected in recent PBMC or gut or lymph node biopsy samples. C135 has a consistently weak antibody response and a substantial CD4+ T cell proliferative response to a previously described HLA-DR13-restricted epitope of HIV-1 p24 , which augmented a CD8+ T cell response to an immunodominant HLA-B57-restricted epitope of p24, while his T cells show reduced levels of CCR5.

Conclusions: Subject C135's early PCR and weak antibody results are consistent with limited infection with a poorly replicating /LTR-deleted strain of HIV-1. With his HLA-B57-restricted gag-specific CD8 and helper HLA-DR13-restricted CD4 T cell proliferative responses, C135 appears to have cleared his HIV-1 infection 37 years after transfusion.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6543488PMC
April 2019

Source-space EEG neurofeedback links subjective experience with brain activity during effortless awareness meditation.

Neuroimage 2017 05 26;151:117-127. Epub 2016 Feb 26.

Center for Mindfulness, University of Massachusetts Medical School, Worcester, MA, USA; Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA. Electronic address:

Background: Meditation is increasingly showing beneficial effects for psychiatric disorders. However, learning to meditate is not straightforward as there are no easily discernible outward signs of performance and thus no direct feedback is possible. As meditation has been found to correlate with posterior cingulate cortex (PCC) activity, we tested whether source-space EEG neurofeedback from the PCC followed the subjective experience of effortless awareness (a major component of meditation), and whether participants could volitionally control the signal.

Methods: Sixteen novice meditators and sixteen experienced meditators participated in the study. Novice meditators were briefly trained to perform a basic meditation practice to induce the subjective experience of effortless awareness in a progressively more challenging neurofeedback test-battery. Experienced meditators performed a self-selected meditation practice to induce this state in the same test-battery. Neurofeedback was provided based on gamma-band (40-57Hz) PCC activity extracted using a beamformer algorithm. Associations between PCC activity and the subjective experience of effortless awareness were assessed by verbal probes.

Results: Both groups reported that decreased PCC activity corresponded with effortless awareness (P<0.0025 for each group), with high median confidence ratings (novices: 8 on a 0-10 Likert scale; experienced: 9). Both groups showed high moment-to-moment median correspondence ratings between PCC activity and subjective experience of effortless awareness (novices: 8, experienced: 9). Both groups were able to volitionally control the PCC signal in the direction associated with effortless awareness by practicing effortless awareness meditation (novices: median % of time=77.97, P=0.001; experienced: 89.83, P<0.0005).

Conclusions: These findings support the feasibility of using EEG neurofeedback to link an objective measure of brain activity with the subjective experience of effortless awareness, and suggest potential utility of this paradigm as a tool for meditation training.
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http://dx.doi.org/10.1016/j.neuroimage.2016.02.047DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5001938PMC
May 2017

pH dependence of cyanide and imidazole binding to the heme domains of Sinorhizobium meliloti and Bradyrhizobium japonicum FixL.

J Inorg Biochem 2015 Dec 22;153:88-102. Epub 2015 Oct 22.

Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115, United States of America. Electronic address:

Equilibrium and kinetic properties of cyanide and imidazole binding to the heme domains of Sinorhizobium meliloti and Bradyrhizobium japonicum FixL (SmFixLH and BjFixLH) have been investigated between pH5 and 11. KD determinations were made at integral pH values, with the strongest binding at pH9 for both ligands. KD for the cyanide complexes of BjFixLH and SmFixLH is 0.15±0.09 and 0.50±0.20μM, respectively, and 0.70±0.01mM for imido-BjFixLH. The association rate constants are pH dependent with maximum values of 443±8 and 252±61M(-1)s(-1) for cyano complexes of BjFixLH and SmFixLH and (5.0±0.3)×10(4) and (7.0±1.4)×10(4)M(-1)s(-1) for the imidazole complexes. The dissociation rate constants are essentially independent of pH above pH5; (1.2±0.3)×10(-4) and (1.7±0.3)×10(-4)s(-1) for the cyano complexes of BjFixLH and SmFixLH, and (73±19) and (77±14) s(-1) for the imidazole complexes. Two ionizable groups in FixLH affect the rate of ligand binding. The more acidic group, identified as the heme 6 propionic acid, has a pKa of 7.6±0.2 in BjFixLH and 6.8±0.2 in SmFixLH. The second ionization is due to formation of hydroxy-FixLH with pKa values of 9.64±0.05 for BjFixLH and 9.61±0.05 for SmFixLH. Imidazole binding is limited by the rate of heme pocket opening with maximum observed values of 680 and 1270s(-1) for BjFixLH and SmFixLH, respectively.
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http://dx.doi.org/10.1016/j.jinorgbio.2015.10.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4690814PMC
December 2015

GLUT1 reductions exacerbate Alzheimer's disease vasculo-neuronal dysfunction and degeneration.

Nat Neurosci 2015 Apr 2;18(4):521-530. Epub 2015 Mar 2.

Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA.

The glucose transporter GLUT1 at the blood-brain barrier (BBB) mediates glucose transport into the brain. Alzheimer's disease is characterized by early reductions in glucose transport associated with diminished GLUT1 expression at the BBB. Whether GLUT1 reduction influences disease pathogenesis remains, however, elusive. Here we show that GLUT1 deficiency in mice overexpressing amyloid β-peptide (Aβ) precursor protein leads to early cerebral microvascular degeneration, blood flow reductions and dysregulation and BBB breakdown, and to accelerated amyloid β-peptide (Aβ) pathology, reduced Aβ clearance, diminished neuronal activity, behavioral deficits, and progressive neuronal loss and neurodegeneration that develop after initial cerebrovascular degenerative changes. We also show that GLUT1 deficiency in endothelium, but not in astrocytes, initiates the vascular phenotype as shown by BBB breakdown. Thus, reduced BBB GLUT1 expression worsens Alzheimer's disease cerebrovascular degeneration, neuropathology and cognitive function, suggesting that GLUT1 may represent a therapeutic target for Alzheimer's disease vasculo-neuronal dysfunction and degeneration.
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http://dx.doi.org/10.1038/nn.3966DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4734893PMC
April 2015

Development, manufacturing and characterization of a highly purified, liquid immunoglobulin g preparation from human plasma.

Transfus Med Hemother 2014 Jun 14;41(3):205-12. Epub 2014 Apr 14.

Department of Clinical Biochemistry and Immunology, Statens Serum Institut, Copenhagen, Denmark.

Background: The use of plasma-derived immunoglobulin G (IgG) is increasing, and the number of diseases, including immunodeficiencies, neurological diseases and autoimmune conditions, treated with intravenous IgG (IVIG) is expanding. Consequently, there is a great need for high-yield production processes for plasma-derived IgG. The aim of this work was to develop a high-yield process leading to a highly purified, liquid, ready-to-use IgG for intravenous use.

Methods: Plasma from healthy, voluntary, non-remunerated donors was fractionated by ethanol precipitation. IgG was extracted from fraction II + III using a phosphate/acetate buffer, pH 4, and purified by chromatography.

Results: Precipitation with 6% polyethylene glycol at pH 7 removed high molecular-weight contaminating proteins, aggregates and contaminating viruses. Ion exchange chromatography at pH 5.7 on serially connected anion and cation exchange columns allowed for elution of IgG from the cation exchange column in good yield and high purity. Further safety was achieved by solvent/detergent treatment and repeated ion exchange chromatography. The product consisted of essentially only IgG monomers and dimers, and had a high purity with very low levels of IgM and IgA.

Conclusion: A process providing highly purified IVIG in good yield was developed.
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http://dx.doi.org/10.1159/000357982DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4086766PMC
June 2014

ROHHADNET syndrome presenting as major behavioral changes in a 5-year-old obese girl.

Pediatrics 2014 Aug 21;134(2):e586-9. Epub 2014 Jul 21.

Division of Pediatric Critical Care, Department of Pediatrics.

Behavioral issues are a frequent problem in the pediatric population. Often, these are evaluated and considered to be psychiatric in origin. We report on a pediatric patient who presented with severe behavioral disturbance and developed organic symptoms including hypoventilation and dysautonomia and who was ultimately diagnosed with ROHHADNET syndrome, a syndrome of rapid-onset obesity, hypothalamic dysfunction, hypoventilation, and autonomic dysregulation associated with a neuroendocrine tumor. Autopsy findings revealed novel findings of the syndrome, including hypothalamic encephalitis.
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http://dx.doi.org/10.1542/peds.2013-2582DOI Listing
August 2014

A randomized clinical trial of the immunogenicity of 7-valent pneumococcal conjugate vaccine compared to 23-valent polysaccharide vaccine in frail, hospitalized elderly.

PLoS One 2014 23;9(4):e94578. Epub 2014 Apr 23.

Westmead Clinical School, Westmead Hospital, and the George Institute for Global Health, The University of Sydney, Sydney, Australia.

Background: Elderly people do not mount strong immune responses to vaccines. We compared 23-valent capsular polysaccharide (23vPPV) alone versus 7-valent conjugate (PCV7) vaccine followed by 23vPPV 6 months later in hospitalized elderly.

Methods: Participants were randomized to receive 23vPPV or PCV7-23vPPV. Antibodies against serotypes 3, 4, 6A, 6B, 9V, 14, 18C, 19A, 19F, 23F were measured by enzyme-linked immunosorbent (ELISA) and opsonophagocytic (OPA) assays at baseline, 6 months and 12 months.

Results: Of 312 recruited, between 40% and 72% of subjects had undetectable OPA titres at baseline. After one dose, PCV7 recipients had significantly higher responses to serotypes 9V (both assays) and 23F (OPA only), and 23vPPV recipients had significantly higher responses to serotype 3 (ELISA), 19F and 19A (OPA only). In subjects with undetectable OPA titres at baseline, a proportionately greater rise in OPA titre (P<0.01) was seen for all serotypes after both vaccines. The GMT ratio of OPA was significantly higher at 12 months in the PCV7-23vPPV group for serotypes 6A, 9V, 18C and 23F. OPA titre levels for these serotypes increased moderately after 6 months, whereas immunity waned in the 23vPPV only arm.

Conclusion: We did not show overwhelming benefit of one vaccine over the other. Low baseline immunity does not preclude a robust immune response, reiterating the importance of vaccinating the frail elderly. A schedule of PCV7-23vPPV prevents waning of antibody, suggesting that both vaccines could be useful in the elderly. Follow up studies are needed to determine persistence of immunity.

Trial Registration: The Australian Clinical Trials Registry ACTRN12607000387426.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0094578PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3997415PMC
January 2015

Blood-spinal cord barrier disruption contributes to early motor-neuron degeneration in ALS-model mice.

Proc Natl Acad Sci U S A 2014 Mar 3;111(11):E1035-42. Epub 2014 Mar 3.

Zilkha Neurogenetic Institute, Center for Neurodegeneration and Regeneration, Department of Physiology and Biophysics, University of Southern California, Los Angeles, CA 90089.

Humans with ALS and transgenic rodents expressing ALS-associated superoxide dismutase (SOD1) mutations develop spontaneous blood-spinal cord barrier (BSCB) breakdown, causing microvascular spinal-cord lesions. The role of BSCB breakdown in ALS disease pathogenesis in humans and mice remains, however, unclear, although chronic blood-brain barrier opening has been shown to facilitate accumulation of toxic blood-derived products in the central nervous system, resulting in secondary neurodegenerative changes. By repairing the BSCB and/or removing the BSCB-derived injurious stimuli, we now identify that accumulation of blood-derived neurotoxic hemoglobin and iron in the spinal cord leads to early motor-neuron degeneration in SOD1(G93A) mice at least in part through iron-dependent oxidant stress. Using spontaneous or warfarin-accelerated microvascular lesions, motor-neuron dysfunction and injury were found to be proportional to the degree of BSCB disruption at early disease stages in SOD1(G93A) mice. Early treatment with an activated protein C analog restored BSCB integrity that developed from spontaneous or warfarin-accelerated microvascular lesions in SOD1(G93A) mice and eliminated neurotoxic hemoglobin and iron deposits. Restoration of BSCB integrity delayed onset of motor-neuron impairment and degeneration. Early chelation of blood-derived iron and antioxidant treatment mitigated early motor-neuronal injury. Our data suggest that BSCB breakdown contributes to early motor-neuron degeneration in ALS mice and that restoring BSCB integrity during an early disease phase retards the disease process.
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http://dx.doi.org/10.1073/pnas.1401595111DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3964055PMC
March 2014

Symptom response following acute bouts of exercise in concussed and non-concussed individuals - a systematic narrative review.

Phys Ther Sport 2013 Nov 10;14(4):253-8. Epub 2013 Jul 10.

Centre for Health, Activity and Rehabilitation Research, School of Physiotherapy, University of Otago, PO Box 56, Dunedin 9054, New Zealand. Electronic address:

Background: Athletes suspected of being concussed are frequently evaluated on the side-line for self-reported symptoms which guide subsequent management and return-to-play decisions. Concussion-like symptoms have been shown to be influenced by prior participation in physical activity; however, the potential contribution of acute exercise on symptoms is not well understood.

Objective: The purpose of this study was to systematically review the literature in order to further understand the acute effects of exercise on documented self-reported symptoms in both concussed and non-concussed individuals.

Design: Systematic narrative review.

Methods: Nine electronic databases were systematically searched using keywords and MeSH terms that included; self-reported symptoms, sports-related concussion, brain concussion, exercise and athletic injuries. In addition, an extensive search of the grey literature was conducted.

Results: Of the 785 articles retrieved, only five met the inclusion criteria comprising a total of 295 concussed and non-concussed participants. In general, the mean symptom scores increased from pre-exercise to post-exercise levels immediately following acute bouts of exercise in both concussed and non-concussed individuals.

Conclusion: Although the symptom scores increased following exercise in both concussed and non-concussed participants, this increase was only maintained for a relatively short duration. Thus, the application to real world situation is still to be established.
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http://dx.doi.org/10.1016/j.ptsp.2013.06.002DOI Listing
November 2013

Deficiency in mural vascular cells coincides with blood-brain barrier disruption in Alzheimer's disease.

Brain Pathol 2013 May 28;23(3):303-10. Epub 2012 Nov 28.

Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, USA.

Neurovascular dysfunction contributes to Alzheimer's disease (AD). Cerebrovascular abnormalities and blood-brain barrier (BBB) damage have been shown in AD. The BBB dysfunction can lead to leakage of potentially neurotoxic plasma components in brain that may contribute to neuronal injury. Pericytes are integral in maintaining the BBB integrity. Pericyte-deficient mice develop a chronic BBB damage preceding neuronal injury. Moreover, loss of pericytes was associated with BBB breakdown in patients with amyotrophic lateral sclerosis. Here, we demonstrate a decrease in mural vascular cells in AD, and show that pericyte number and coverage in the cortex and hippocampus of AD subjects compared with neurologically intact controls are reduced by 59% and 60% (P < 0.01), and 32% and 33% (P < 0.01), respectively. An increase in extravascular immunoglobulin G (IgG) and fibrin deposition correlated with reductions in pericyte coverage in AD cases compared with controls; the Pearson's correlation coefficient r for the magnitude of BBB breakdown to IgG and fibrin vs. reduction in pericyte coverage was -0.96 (P < 0.01) and -0.81 (P < 0.01) in the cortex, respectively, and -0.86 (P < 0.01) and -0.98 (P < 0.01) in the hippocampus, respectively. Thus, deficiency in mural vascular cells may contribute to disrupted vascular barrier properties and resultant neuronal dysfunction during AD pathogenesis.
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http://dx.doi.org/10.1111/bpa.12004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3628957PMC
May 2013

Blood-spinal cord barrier breakdown and pericyte reductions in amyotrophic lateral sclerosis.

Acta Neuropathol 2013 Jan 1;125(1):111-20. Epub 2012 Sep 1.

Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute, University of Southern California, Room: 101, 1501 San Pablo Street, Los Angeles, CA 90089, USA.

The blood-brain barrier and blood-spinal cord barrier (BSCB) limit the entry of plasma components and erythrocytes into the central nervous system (CNS). Pericytes play a key role in maintaining blood-CNS barriers. The BSCB is damaged in patients with amyotrophic lateral sclerosis (ALS). Moreover, transgenic ALS rodents and pericyte-deficient mice develop BSCB disruption with erythrocyte extravasation preceding motor neuron dysfunction. Here, we studied whether BSCB disruption with erythrocyte extravasation and pericyte loss are present in human ALS. We show that 11 of 11 cervical cords from ALS patients, but 0 of 5 non-neurodegenerative disorders controls, possess perivascular deposits of erythrocyte-derived hemoglobin and hemosiderin typically 10-50 μm in diameter suggestive of erythrocyte extravasation. Immunostaining for CD235a, a specific marker for erythrocytes, confirmed sporadic erythrocyte extravasation in ALS, but not controls. Quantitative analysis revealed a 3.1-fold increase in perivascular hemoglobin deposits in ALS compared to controls showing hemoglobin confined within the vascular lumen, which correlated with 2.5-fold increase in hemosiderin deposits (r = 0.82, p < 0.01). Spinal cord parenchymal accumulation of plasma-derived immunoglobulin G, fibrin and thrombin was demonstrated in ALS, but not controls. Immunostaining for platelet-derived growth factor receptor-β, a specific marker for CNS pericytes, indicated a 54 % (p < 0.01) reduction in pericyte number in ALS patients compared to controls. Pericyte reduction correlated negatively with the magnitude of BSCB damage as determined by hemoglobin abundance (r = -0.75, p < 0.01). Thus, the BSCB disruption with erythrocyte extravasation and pericyte reductions is present in ALS. Whether similar findings occur in motor cortex and affected brainstem motor nuclei remain to be seen.
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http://dx.doi.org/10.1007/s00401-012-1039-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3535352PMC
January 2013

Seasoned adaptive antibody immunity for highly pathogenic pandemic influenza in humans.

Immunol Cell Biol 2012 Feb 7;90(2):149-58. Epub 2011 Jun 7.

Biosafety, Immunobiology, Global Health and Pandemic Infections Research, Central Clinical School, The University of Sydney, Camperdown, New South Wales, Australia.

Fundamentally new approaches are required for the development of vaccines to pre-empt and protect against emerging and pandemic influenzas. Current strategies involve post-emergent homotypic vaccines that are modelled upon select circulating 'seasonal' influenzas, but cannot induce cross-strain protection against newly evolved or zoonotically introduced highly pathogenic influenza (HPI). Avian H5N1 and the less-lethal 2009 H1N1 and their reassortants loom as candidates to seed a future HPI pandemic. Therefore, more universal 'seasoned' vaccine approaches are urgently needed for heterotypic protection ahead of time. Pivotal to this is the need to understand mechanisms that can deliver broad strain protection. Heterotypic and heterosubtypic humoral immunities have largely been overlooked for influenza cross-protection, with most 'seasoned' vaccine efforts for humans focussed on heterotypic cellular immunity. However, 5 years ago we began to identify direct and indirect indicators of humoral-herd immunity to protein sites preserved among H1N1, H3N2 and H5N1 influenzas. Since then the evidence for cross-protective antibodies in humans has been accumulating. Now proposed is a rationale to stimulate and enhance pre-existing heterotypic humoral responses that, together with cell-mediated initiatives, will deliver pre-emptive and universal human protection against emerging epidemic and pandemic influenzas.
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http://dx.doi.org/10.1038/icb.2011.38DOI Listing
February 2012

Heterosubtypic anti-avian H5N1 influenza antibodies in intravenous immunoglobulins from globally separate populations protect against H5N1 infection in cell culture.

J Mol Genet Med 2009 Dec 23;3(2):217-24. Epub 2009 Dec 23.

Biosafety, Immunobiology, Global Health and Pandemic Infections Research, Central Clinical School, Faculty of Medicine, The University of Sydney, Camperdown, NSW 2006, Australia.

With antigenically novel epidemic and pandemic influenza strains persistently on the horizon it is of fundamental importance that we understand whether heterosubtypic antibodies gained from exposures to circulating human influenzas exist and can protect against emerging novel strains. Our studies of IVIG obtained from an infection-naive population (Australian) enabled us to reveal heterosubtypic influenza antibodies that cross react with H5N1. We now expand those findings for an Australian donor population to include IVIG formulations from a variety of northern hemisphere populations. Examination of IVIGs from European and South East-Asian (Malaysian) blood donor populations further reveal heterosubtypic antibodies to H5N1 in humans from different global regions. Importantly these protect against highly pathogenic avian H5N1 infection in vitro, albeit at low titres of inhibition. Although there were qualitative and quantitative differences in binding and protection between globally different formulations, the heterosubtypic antibody activities for the respective IVIGs were in general quite similar. Of particular note because of the relative geographic proximity to the epicentre of H5N1 and the majority of human infections, was the similarity in the antibody binding responses between IVIGs from the Malayan peninsula, Europe and Australia. These findings highlight the value of employing IVIGs for the study of herd immunity, and particularly heterosubtypic antibody responses to viral antigens such as those conserved between circulating human influenzas and emerging influenza strains such as H5N1. They also open a window into a somewhat ill defined arena of antibody immunity, namely heterosubtypic immunity.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2805843PMC
http://dx.doi.org/10.4172/1747-0862.1000038DOI Listing
December 2009

Acquired heterosubtypic antibodies in human immunity for avian H5N1 influenza.

J Mol Genet Med 2009 Dec 15;3(2):205-9. Epub 2009 Dec 15.

Well understood are the adaptive and dramatic neutralizing homosubtypic antibody responses to hypervariable, immunodominant sites of the hemagglutinin (HA) and neuraminidase (NA) of individual influenza strains. These define influenza subtypes and vaccines modelled upon their HA and NA antigens provide seasonal neutralizing antibody protection against subsequent exposure to the strain and its close relatives, but give little if any protection against antigenically drifted or shifted strains. Contrasting to this is a different form of acquired antibody response, called heterosubtypic immunity. This provides a more seasoned adaptive antibody response to immune-recessive epitopes that are highly-conserved amongst strains. Although, such responses are of lower individual amplitudes than seasonal mechanisms they are active across influenza subtypes, and may give pre-emptive protection against new strains yet to emerge. Heterosubtypic immunities have been well studied in animals, but surprisingly there is minimal evidence for this type of antibody immunity in humans. Thus championed is the notion that seasoned humoral responses can through repeated exposure to sites widely conserved across different strains, cumulatively provide humans with a level of broad protection against emergent novel strains, such as H5N1, that is not afforded by seasonal humoral responses.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2805841PMC
http://dx.doi.org/10.4172/1747-0862.1000036DOI Listing
December 2009

HIV-1 evades virus-specific IgG2 and IgA responses by targeting systemic and intestinal B cells via long-range intercellular conduits.

Nat Immunol 2009 Sep 2;10(9):1008-17. Epub 2009 Aug 2.

Department of Pathology and Laboratory Medicine, Weill Medical College of Cornell University, New York, New York, USA.

Contact-dependent communication between immune cells generates protection but also facilitates viral spread. Here we found that macrophages formed long-range actin-propelled conduits in response to negative factor (Nef), a human immunodeficiency virus type 1 (HIV-1) protein with immunosuppressive functions. Conduits attenuated immunoglobulin G2 (IgG2) and IgA class switching in systemic and intestinal lymphoid follicles by shuttling Nef from infected macrophages to B cells through a guanine-exchange factor-dependent pathway involving the amino-terminal anchor, central core and carboxy-terminal flexible loop of Nef. By showing stronger virus-specific IgG2 and IgA responses in patients with Nef-deficient virions, our data suggest that HIV-1 exploits intercellular 'highways' as a 'Trojan horse' to deliver Nef to B cells and evade humoral immunity systemically and at mucosal sites of entry.
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http://dx.doi.org/10.1038/ni.1753DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2784687PMC
September 2009

Mechanisms of HIV non-progression; robust and sustained CD4+ T-cell proliferative responses to p24 antigen correlate with control of viraemia and lack of disease progression after long-term transfusion-acquired HIV-1 infection.

Retrovirology 2008 Dec 11;5:112. Epub 2008 Dec 11.

Australian Red Cross Blood Service, 153 Clarence Street, Sydney, NSW 2000, Australia.

Background: Elite non-progressors (plasma viral load < 50 copies/ml while antiretroviral naive) constitute a tiny fraction of HIV-infected individuals. After 12 years follow-up of a cohort of 13 long-term non-progressors (LTNP) identified from 135 individuals with transfusion-acquired HIV infection, 5 remained LTNP after 23 to 26 years infection, but only 3 retained elite LTNP status. We examined the mechanisms that differentiated delayed progressors from LTNP in this cohort.

Results: A survival advantage was conferred on 12 of 13 subjects, who had at least one host genetic factor (HLA, chemokine receptor or TLR polymorphisms) or viral attenuating factor (defective nef) associated with slow progression. However, antiviral immune responses differentiated the course of disease into and beyond the second decade of infection. A stable p24-specific proliferative response was associated with control of viraemia and retention of non-progressor status, but this p24 response was absent or declined in viraemic subjects. Strong Gag-dominant cytotoxic T lymphocyte (CTL) responses were identified in most LTNP, or Pol dominant-CTL in those with nef-defective HIV infection. CTL were associated with control of viraemia when combined with p24 proliferative responses. However, CTL did not prevent late disease progression. Individuals with sustained viral suppression had CTL recognising numerous Gag epitopes, while strong but restricted responses to one or two immunodominant epitopes was effective for some time, but failed to contain viraemia over the course of this study. Viral escape mutants at a HLA B27-restricted Gag-p24 epitope were detected in only 1 of 3 individuals, whereas declining or negative p24 proliferative responses occurred in all 3 concurrent with an increase in viraemia.

Conclusion: Detectable viraemia at study entry was predictive of loss of LTNP status and/or disease progression in 6 of 8, and differentiated slow progressors from elite LTNP who retained potent virological control. Sustained immunological suppression of viraemia was independently associated with preserved p24 proliferative responses, regardless of the strength and breadth of the CTL response. A decline in this protective p24 response preceded or correlated with loss of non-progressor status and/or signs of disease progression.
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http://dx.doi.org/10.1186/1742-4690-5-112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2633348PMC
December 2008

Replication-dependent pathogenicity of attenuated nef-deleted HIV-1 in vivo.

J Acquir Immune Defic Syndr 2007 Dec;46(4):390-4

Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia.

Background: The Sydney Blood Bank Cohort (SBBC) of long-term survivors consists of 8 individuals infected with an attenuated nef-deleted strain of HIV-1 by means of contaminated blood products donated from a common blood donor between 1981 and 1984. We report the outcome of a 26-year prospective study documenting the clinical course of nef-deleted HIV-1 infection in 7 SBBC members.

Methods: CD4 T-cell counts and plasma HIV-1 RNA levels were measured by flow cytometry and the COBAS AMPLICOR HIV-1 monitor version 1 or 1.5 (Roche Molecular Diagnostic Systems, Branchburg, NJ), respectively. Changes in these parameters with time were determined by least-squares analysis using STATA (StataCorp, College Station, TX) statistical software.

Results: Four subjects had persistent low-level viremia. Of these, progression to AIDS and/or evidence of CD4 T-cell loss occurred in 3; the fourth viremic individual died of non-HIV-1-related causes in 1995, only 12 years after infection. Three subjects have persistently undetectable plasma HIV-1 RNA levels and remain long-term nonprogressors.

Conclusions: Our study shows that even weakened highly attenuated HIV-1 strains with nef deletions are ultimately pathogenic in humans unless replication is completely and persistently suppressed in vivo. This finding underscores the importance of aiming to achieve nothing less than complete and sustained suppression of HIV-1 replication by antiretroviral drugs and vaccines.
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http://dx.doi.org/10.1097/QAI.0b013e31815aba08DOI Listing
December 2007

High prevalence of the CD14-159CC genotype in patients infected with severe acute respiratory syndrome-associated coronavirus.

Clin Vaccine Immunol 2007 Dec 3;14(12):1644-5. Epub 2007 Oct 3.

Cell Biology Laboratory, ARCBS-Endeavour, 153 Clarence Street, Sydney, NSW 2000, Australia.

To investigate whether genetic factors of innate immunity might influence susceptibility and/or progression in individuals infected with SARS, we evaluated the CD14 gene polymorphism in 198 Hong Kong blood donors and 152 Hong Kong severe acute respiratory syndrome (SARS) patients who were previously genotyped for FcgammaRIIA polymorphisms. The prevalence of the CD14-159CC polymorphism was significantly higher in the patients with severe SARS than in the those with mild SARS or controls (31% versus 15% [mild SARS] or 20% [controls]; mild SARS: P = 0.029; odds ratio, 2.74; 95% confidence interval, 1.15 to 6.57; controls, P = 0.04; odds ratio, 2.41; 95% confidence interval, 1.05 to 5.54), and both CD14-159CC and FcgammaRIIA-RR131 are risk genotypes for severe SARS-CoV infection.
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http://dx.doi.org/10.1128/CVI.00100-07DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2168372PMC
December 2007

Pathogenicity and immunogenicity of attenuated, nef-deleted HIV-1 strains in vivo.

Retrovirology 2007 Sep 23;4:66. Epub 2007 Sep 23.

Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia.

In efforts to develop an effective vaccine, sterilizing immunity to primate lentiviruses has only been achieved by the use of live attenuated viruses carrying major deletions in nef and other accessory genes. Although live attenuated HIV vaccines are unlikely to be developed due to a myriad of safety concerns, opportunities exist to better understand the correlates of immune protection against HIV infection by studying rare cohorts of long-term survivors infected with attenuated, nef-deleted HIV strains such as the Sydney blood bank cohort (SBBC). Here, we review studies of viral evolution, pathogenicity, and immune responses to HIV infection in SBBC members. The studies show that potent, broadly neutralizing anti-HIV antibodies and robust CD8+ T-cell responses to HIV infection were not necessary for long-term control of HIV infection in a subset of SBBC members, and were not sufficient to prevent HIV sequence evolution, augmentation of pathogenicity and eventual progression of HIV infection in another subset. However, a persistent T-helper proliferative response to HIV p24 antigen was associated with long-term control of infection. Together, these results underscore the importance of the host in the eventual outcome of infection. Thus, whilst generating an effective antibody and CD8+ T-cell response are an essential component of vaccines aimed at preventing primary HIV infection, T-helper responses may be important in the generation of an effective therapeutic vaccine aimed at blunting chronic HIV infection.
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http://dx.doi.org/10.1186/1742-4690-4-66DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2075523PMC
September 2007

Phenotype and envelope gene diversity of nef-deleted HIV-1 isolated from long-term survivors infected from a single source.

Virol J 2007 Jul 16;4:75. Epub 2007 Jul 16.

Macfarlane Burnet Institute for Medical Research and Public Health, Victoria, Australia.

Background: The Sydney blood bank cohort (SBBC) of long-term survivors consists of multiple individuals infected with attenuated, nef-deleted variants of human immunodeficiency virus type 1 (HIV-1) acquired from a single source. Long-term prospective studies have demonstrated that the SBBC now comprises slow progressors (SP) as well as long-term nonprogressors (LTNP). Convergent evolution of nef sequences in SBBC SP and LTNP indicates the in vivo pathogenicity of HIV-1 in SBBC members is dictated by factors other than nef. To better understand mechanisms underlying the pathogenicity of nef-deleted HIV-1, we examined the phenotype and env sequence diversity of sequentially isolated viruses (n = 2) from 3 SBBC members.

Results: The viruses characterized here were isolated from two SP spanning a three or six year period during progressive HIV-1 infection (subjects D36 and C98, respectively) and from a LTNP spanning a two year period during asymptomatic, nonprogressive infection (subject C18). Both isolates from D36 were R5X4 phenotype and, compared to control HIV-1 strains, replicated to low levels in peripheral blood mononuclear cells (PBMC). In contrast, both isolates from C98 and C18 were CCR5-restricted. Both viruses isolated from C98 replicated to barely detectable levels in PBMC, whereas both viruses isolated from C18 replicated to low levels, similar to those isolated from D36. Analysis of env by V1V2 and V3 heteroduplex tracking assay, V1V2 length polymorphisms, sequencing and phylogenetic analysis showed distinct intra- and inter-patient env evolution.

Conclusion: Independent evolution of env despite convergent evolution of nef may contribute to the in vivo pathogenicity of nef-deleted HIV-1 in SBBC members, which may not necessarily be associated with changes in replication capacity or viral coreceptor specificity.
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http://dx.doi.org/10.1186/1743-422X-4-75DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1939844PMC
July 2007

Substantial improvements in performance indicators achieved in a peripheral blood mononuclear cell cryopreservation quality assurance program using single donor samples.

Clin Vaccine Immunol 2007 Jan 18;14(1):52-9. Epub 2006 Oct 18.

Australian Red Cross Blood Service, 153 Clarence Street, Sydney, NSW 2000, Australia.

Storage of high-quality cryopreserved peripheral blood mononuclear cells (PBMC) is often a requirement for multicenter clinical trials and requires a reproducibly high standard of practice. A quality assurance program (QAP) was established to assess an Australia-wide network of laboratories in the provision of high-quality PBMC (determined by yield, viability, and function), using blood taken from single donors (human immunodeficiency virus [HIV] positive and HIV negative) and shipped to each site for preparation and cryopreservation of PBMC. The aim of the QAP was to provide laboratory accreditation for participation in clinical trials and cohort studies which require preparation and cryopreservation of PBMC and to assist all laboratories to prepare PBMC with a viability of >80% and yield of >50% following thawing. Many laboratories failed to reach this standard on the initial QAP round. Interventions to improve performance included telephone interviews with the staff at each laboratory, two annual wet workshops, and direct access to a senior scientist to discuss performance following each QAP round. Performance improved substantially in the majority of sites that initially failed the QAP (P = 0.002 and P = 0.001 for viability and yield, respectively). In a minority of laboratories, there was no improvement (n = 2), while a high standard was retained at the laboratories that commenced with adequate performance (n = 3). These findings demonstrate that simple interventions and monitoring of PBMC preparation and cryopreservation from multiple laboratories can significantly improve performance and contribute to maintenance of a network of laboratories accredited for quality PBMC fractionation and cryopreservation.
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http://dx.doi.org/10.1128/CVI.00214-06DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1797705PMC
January 2007

CD127+CCR5+CD38+++ CD4+ Th1 effector cells are an early component of the primary immune response to vaccinia virus and precede development of interleukin-2+ memory CD4+ T cells.

J Virol 2006 Oct;80(20):10151-61

Centre for Immunology, St. Vincent's Hospital, Victoria Street, Darlinghurst, NSW 2010, Australia.

The stages of development of human antigen-specific CD4+ T cells responding to viral infection and their differentiation into long-term memory cells are not well understood. The inoculation of healthy adults with vaccinia virus presents an opportunity to study these events intensively. Between days 11 and 14 postinoculation, there was a peak of proliferating CCR5+CD38+++ CD4+ effector cells which contained the cytotoxic granule marker T-cell intracellular antigen 1 and included gamma interferon (IFN-gamma)-producing vaccinia virus-specific CD4+ T cells. The majority of these initial vaccinia virus-specific CD4+ T cells were CD127+ and produced interleukin-2 (IL-2) but not CTLA-4 in response to restimulation in vitro. Between days 14 and 21, there was a switch from IFN-gamma and IL-2 coexpression to IL-2 production only, coinciding with a resting phenotype and an increased in vitro proliferation response. The early CCR5+CD38+++ vaccinia virus-specific CD4+ T cells were similar to our previous observations of human immunodeficiency virus (HIV)-specific CD4+ T cells in primary HIV type 1 (HIV-1) infection, but the vaccinia virus-specific cells expressed much more CD127 and IL-2 than we previously found in their HIV-specific counterparts. The current study provides important information on the differentiation of IL-2+ vaccinia virus-specific memory cells, allowing further study of antiviral effector CD4+ T cells in healthy adults and their dysfunction in HIV-1 infection.
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http://dx.doi.org/10.1128/JVI.02670-05DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1617315PMC
October 2006

Transcriptional activity of blood-and cerebrospinal fluid-derived nef/long-terminal repeat sequences isolated from a slow progressor infected with nef-deleted human immunodeficiency virus type 1 (HIV-1) who developed HIV-associated dementia.

J Neurovirol 2006 Jun;12(3):219-28

The Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia.

The authors studied the transcriptional activity of blood-and cerebrospinal fluid (CSF)-derived nef/long-terminal repeat (LTR) sequences isolated from a slow progressor infected with nef-deleted human immunodeficiency virus type 1 (HIV-1) who developed HIV-associated dementia (HIVD). The transcriptional activity of CSF-derived nef/LTR clones isolated during HIVD was up to 4.5-fold higher than blood-derived clones isolated before and during HIVD when tested under basal, phorbol 12-myristate 13-acetate-(PMA-), and Tat-activated conditions, and was associated with the presence of duplicated nuclear factor (NF)-kappaB and specificity factor-1 (Sp-1) binding sites coupled with a truncated nef sequence, increased replication capacity, and high CSF viral load. Thus, nef and LTR mutations that augment transcription may contribute to neuropathogenesis of nef-deleted HIV-1.
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http://dx.doi.org/10.1080/13550280600827369DOI Listing
June 2006

Genetic analyses reveal structured HIV-1 populations in serially sampled T lymphocytes of patients receiving HAART.

Virology 2006 Apr 7;348(1):35-46. Epub 2006 Feb 7.

Retroviral Genetics Laboratory, Center for Virus Research, Westmead Millennium Institute, Westmead Hospital, The University of Sydney, Darcy Road, Westmead, Sydney NSW 2145, Australia.

HIV-1 infection and compartmentalization in diverse leukocyte targets significantly contribute to viral persistence during suppressive highly active antiretroviral therapy (HAART). Longitudinal analyses were performed on envelope sequences of HIV-1 populations from plasma, CD4+ and CD8+ T lymphocytes in 14 patients receiving HAART and 1 therapy-naive individual. Phylogenetic reconstructions and analysis of molecular variance revealed that HIV-1 populations in CD4+ and CD8+ T cells remained compartmentalized over time in most individuals. Analyses of viral genetic variation demonstrated that, despite compartmentalization remaining over time, viral subpopulations tended not to persist and evolve but instead broke down and became reconstituted by new founder viruses. Due to the profound impact of HAART on viral evolution, it was difficult to discern whether these dynamics were ongoing during treatment or predominantly established prior to the commencement of therapy. The genetic structure and viral founder effects observed in serially sampled T lymphocyte populations supported a scenario of metapopulation dynamics in the tissue(s) where different leukocytes become infected, a factor likely to contribute to the highly variable way that drug resistance evolves in different individuals during HAART.
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http://dx.doi.org/10.1016/j.virol.2005.12.031DOI Listing
April 2006

Longitudinal analysis of human immunodeficiency virus type 1 nef/long terminal repeat sequences in a cohort of long-term survivors infected from a single source.

J Virol 2006 Jan;80(2):1047-52

Macfarlane Burnet Institute for Medical Research and Public Health, GPO Box 2284, Melbourne 3001, Victoria, Australia.

We studied the evolution of human immunodeficiency virus type 1 (HIV-1) in a cohort of long-term survivors infected with an attenuated strain of HIV-1 acquired from a single source. Although the cohort members experienced differing clinical courses, we demonstrate similar evolution of HIV-1 nef/long-terminal repeat (LTR) sequences, characterized by progressive sequence deletions tending toward a minimal nef/LTR structure that retains only sequence elements required for viral replication. The in vivo pathogenicity of attenuated HIV-1 is therefore dictated by viral and/or host factors other than those that impose a unidirectional selection pressure on the nef/LTR region of the HIV-1 genome.
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http://dx.doi.org/10.1128/JVI.80.2.1047-1052.2006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1346882PMC
January 2006

Detection of prion epitopes on PrP and PrP of transmissible spongiform encephalopathies using specific monoclonal antibodies to PrP.

Immunol Cell Biol 2005 Dec;83(6):632-7

Australian Red Cross Blood Service-Endeavour, Sydney, New South Wales, Australia.

Amino acid residues 90-120 of the prion protein (PrP) are likely to be critical for the conversion of PrP(c) to PrP(sc) in the transmissible spongiform encephalopathies. We raised 10 monoclonal antibodies against the 90-120 amino acid region, mapped the epitope specificity of these anti-PrP antibodies, and investigated the expression of epitopes recognized by the antibodies in both PrP(c) and PrP(sc). Four out of five of the anti-PrP antibodies raised in a prion knockout mouse immunized with the linear peptide of PrP90-120 could detect PrP(sc) in 'native' and denatured forms and PrP(c) in normal cells, as well as recognize epitopes within PrP93-112 residues. In contrast, the other six anti-PrP reagents, including five raised from the two knockout mice immunized with conformationally modified PrP90-120 peptide, could detect PrP(c) and recognize epitopes within PrP93-107 residues. Four of these reagents could also detect denatured PrP(sc) on western blots but not PrP(sc) plaques in brain tissue. The results indicate that residues PrP93-102 are exposed in PrP(c) but are buried upon conversion to the PrP(sc) isoform. Furthermore, PrP103-107 residues are partially buried in PrP(sc) while only the PrP107-112 epitope remains exposed, suggesting that the region PrP93-112 undergoes conformational changes during its conversion to PrP(sc).
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http://dx.doi.org/10.1111/j.1440-1711.2005.01384.xDOI Listing
December 2005

Bispectral index as a guide for titration of propofol during procedural sedation among children.

Pediatrics 2005 Jun;115(6):1666-74

Division of Pediatric Critical Care, Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA.

Objective: To determine whether the bispectral index (BIS) monitor could be used to guide physicians in titrating propofol to an effective safe level of deep sedation for children undergoing painful medical procedures.

Design: Multiphase clinical trial.

Setting: Outpatient treatment center of a university children's hospital.

Patients: Pediatric outpatients undergoing painful medical procedures.

Interventions: Patients were sedated with propofol for the procedures. Patients were monitored with a BIS monitor, and the BIS score was correlated with the patient's clinical level of sedation. The BIS score was then used as a guide to titrate propofol in the last phase of the study.

Measurements And Main Results: The study consisted of 3 phases. In a chart review of data for 154 children who underwent 212 procedures, propofol was found to be safe and effective, with consistent dosing among the intensivists administering the medication. The children received a mean bolus dose of propofol of 1.56 mg/kg, with a mean total dose of propofol of 0.33 mg/kg per minute for the duration of the procedure. In the second phase, 21 patients ranging in age from 27 weeks to 18 years, with normal neurologic function, were sedated with propofol. An observer who was blinded to the BIS scores recorded clinical levels of sedation and reactivity (with a modified Ramsay scale and reactivity score) every 1 to 3 minutes. Another observer recorded the BIS scores at the same times. A total of 275 data points were collected and evaluated. All data points from the times at which patients were considered to be sedated adequately were used to construct a normal distribution of BIS scores. The mean BIS score was 62. This distribution was used to predict that a maximal BIS score of 47 was needed to ensure adequate sedation for 90% of the population. In the third phase of the study, an algorithm was devised to determine the target BIS score necessary for adequate sedation of 95% of the patients. We chose an initial BIS score of 50 (at which 85% of the patients in phase 2 were sedated) because of the possibility of data from phase 2 being skewed toward oversedation. Propofol was administered by an intensivist in an attempt to maintain the target BIS score. A blinded observer noted the patient's clinical level of sedation. In this group, there were 2 failures, ie, patients were clinically uncomfortable despite a BIS score of < or =50, representing only 90% success. Therefore, with the algorithm, propofol was titrated to sedate the next patients to a BIS score of 45. These patients required a mean bolus dose of 1.47 mg/kg and a mean total dose of 0.51 mg/kg per minute to maintain a BIS score of 45. They awakened in 12.75 minutes. All patients were sedated adequately, all procedures were successful, and no patients experienced complications from the sedation. To eliminate variability in the way propofol was dosed, the next 10 patients were given propofol according to a standardized protocol. These 10 children received an initial bolus of 1 mg/kg, with incremental bolus doses of 0.5 mg/kg per dose (maximum: 20 mg) to achieve and to maintain a BIS score of 45. With this protocol, all patients were sedated adequately and none experienced complications from the sedation. The patients required a mean bolus dose of 2.23 mg/kg and a mean dose of 0.52 mg/kg per minute to maintain a BIS score of 45. The mean time until awakening was 14.9 minutes. Regarding the total dose over time and the time until awakening, there was no statistical significance between this group and the group sedated to a BIS score of 45 without the dosing protocol.

Conclusion: The BIS monitor can be a useful monitoring guide for the titration of propofol by physicians who are competent in airway and hemodynamic management, to achieve deep sedation for children undergoing painful procedures.
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http://dx.doi.org/10.1542/peds.2004-1979DOI Listing
June 2005