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Petrin AL, Machado-Paula LA, Hinkle A, Hovey L, Awotoye W, Chimenti M, Darbro B, Ribeiro-Bicudo LA, Dabdoub SM, Peter T, Breheny P, Murray J, Van Otterloo E, Rengasamy Venugopalan S, Moreno-Uribe LM. Whole genome sequencing of a family with autosomal dominant features within the oculoauriculovertebral spectrum. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.02.07.24301824. [PMID: 38370836 PMCID: PMC10871465 DOI: 10.1101/2024.02.07.24301824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Background Oculoauriculovertebral Spectrum (OAVS) encompasses abnormalities on derivatives from the first and second pharyngeal arches including macrostomia, hemifacial microsomia, micrognathia, preauricular tags, ocular and vertebral anomalies. We present genetic findings on a three-generation family affected with macrostomia, preauricular tags and uni- or bilateral ptosis following an autosomal dominant pattern. Methods We generated whole genome sequencing data for the proband, affected parent and unaffected paternal grandparent followed by Sanger sequencing on 23 family members for the top 10 candidate genes: KCND2, PDGFRA, CASP9, NCOA3, WNT10A, SIX1, MTF1, KDR/VEGFR2, LRRK1, and TRIM2 We performed parent and sibling-based transmission disequilibrium tests and burden analysis via a penalized linear mixed model, for segregation and mutation burden respectively. Next, via bioinformatic tools we predicted protein function, mutation pathogenicity and pathway enrichment to investigate the biological relevance of mutations identified. Results Rare missense mutations in SIX1, KDR/VEGFR2, and PDGFRA showed the best segregation with the OAV phenotypes in this family. When considering any of the 3 OAVS phenotypes as an outcome, SIX1 had the strongest associations in parent-TDTs and sib-TDTs (p=0.025, p=0.052) (unadjusted p-values). Burden analysis identified SIX1 (RC=0.87) and PDGFRA (RC=0.98) strongly associated with OAVS severity. Using phenotype-specific outcomes, sib-TDTs identified SIX1 with uni- or bilateral ptosis (p=0.049) and ear tags (p=0.01), and PDGFRA and KDR/VEGFR2 with ear tags (both p<0.01). Conclusion SIX1, PDGFRA, and KDR/VEGFR2 are strongly associated to OAVS phenotypes. SIX1 has been previously associated with OAVS ear malformations and is co-expressed with EYA1 during ear development. Efforts to strengthen the genotype-phenotype co-relation underlying the OAVS are key to discover etiology, family counseling and prevention.
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Peter T, Malgaretti P, Rivas N, Scagliarini A, Harting J, Dietrich S. Numerical simulations of self-diffusiophoretic colloids at fluid interfaces. SOFT MATTER 2020; 16:3536-3547. [PMID: 32215402 DOI: 10.1039/c9sm02247c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The dynamics of active colloids is very sensitive to the presence of boundaries and interfaces which therefore can be used to control their motion. Here we analyze the dynamics of active colloids adsorbed at a fluid-fluid interface. By using a mesoscopic numerical approach which relies on an approximated numerical solution of the Navier-Stokes equation, we show that when adsorbed at a fluid interface, an active colloid experiences a net torque even in the absence of a viscosity contrast between the two adjacent fluids. In particular, we study the dependence of this torque on the contact angle of the colloid with the fluid-fluid interface and on its surface properties. We rationalize our results via an approximate approach which accounts for the appearance of a local friction coefficient. By providing insight into the dynamics of active colloids adsorbed at fluid interfaces, our results are relevant for two-dimensional self assembly and emulsion stabilization by means of active colloids.
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Schrijver CJ, Beer J, Baltensperger U, Cliver EW, Güdel M, Hudson HS, McCracken KG, Osten RA, Peter T, Soderblom DR, Usoskin IG, Wolff EW. Estimating the frequency of extremely energetic solar events, based on solar, stellar, lunar, and terrestrial records. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012ja017706] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Koeberich S, Rapp T, Stocker J, Waidmann-Papavassilis S, Belzner M, Belter K, Peter T, Warnstadt A, Hajek A, Thielhorn U. P168 Experiences with an education and counselling programme to promote self-care behaviour in hospitalized heart failure patients – a qualitative study. Eur J Cardiovasc Nurs 2011. [DOI: 10.1016/s1474-5151(11)60109-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Koeberich S, Rapp T, Stocker J, Waidmann-Papavassilis S, Belzner M, Belter K, Peter T, Warnstadt A, Hajek A, Thielhorn U. P168 Poster Experiences with an education and counselling programme to promote self-care behaviour in hospitalized heart failure patients -a qualitative study. Eur J Cardiovasc Nurs 2011. [DOI: 10.1016/s1474-51511160109-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Morgenstern O, Akiyoshi H, Bekki S, Braesicke P, Butchart N, Chipperfield MP, Cugnet D, Deushi M, Dhomse SS, Garcia RR, Gettelman A, Gillett NP, Hardiman SC, Jumelet J, Kinnison DE, Lamarque JF, Lott F, Marchand M, Michou M, Nakamura T, Olivié D, Peter T, Plummer D, Pyle JA, Rozanov E, Saint-Martin D, Scinocca JF, Shibata K, Sigmond M, Smale D, Teyssèdre H, Tian W, Voldoire A, Yamashita Y. Anthropogenic forcing of the Northern Annular Mode in CCMVal-2 models. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jd013347] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Scarnato B, Staehelin J, Peter T, Gröbner J, Stübi R. Temperature and slant path effects in Dobson and Brewer total ozone measurements. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2009jd012349] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Zobrist B, Marcolli C, Peter T, Koop T. Heterogeneous Ice Nucleation in Aqueous Solutions: the Role of Water Activity. J Phys Chem A 2008; 112:3965-75. [DOI: 10.1021/jp7112208] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kempf T, Bjorklund E, Olofsson S, Lindahl B, Allhoff T, Peter T, Tongers J, Wollert KC, Wallentin L. Growth-differentiation factor-15 improves risk stratification in ST-segment elevation myocardial infarction. Eur Heart J 2007; 28:2858-65. [DOI: 10.1093/eurheartj/ehm465] [Citation(s) in RCA: 161] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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MacKenzie AR, Schiller C, Peter T, Adriani A, Beuermann J, Bujok O, Cairo F, Corti T, DiDonfrancesco G, Gensch I, Kiemle C, Krämer M, Kröger C, Merkulov S, Oulanovsky A, Ravegnani F, Rohs S, Rudakov V, Salter P, Santacesaria V, Stefanutti L, Yushkov V. Tropopause and hygropause variability over the equatorial Indian Ocean during February and March 1999. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd006639] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Fueglistaler S, Wernli H, Peter T. Tropical troposphere-to-stratosphere transport inferred from trajectory calculations. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2003jd004069] [Citation(s) in RCA: 173] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Koch G, Wernli H, Staehelin J, Peter T. Reply to comment by H. Teitelbaum et al. on “A Lagrangian analysis of stratospheric ozone variability and long-term trends above Payerne (Switzerland) during 1970-2001”. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2003jd003911] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Novitsky V, Gilbert P, Peter T, McLane MF, Gaolekwe S, Rybak N, Thior I, Ndung'u T, Marlink R, Lee TH, Essex M. Association between virus-specific T-cell responses and plasma viral load in human immunodeficiency virus type 1 subtype C infection. J Virol 2003; 77:882-90. [PMID: 12502804 PMCID: PMC140844 DOI: 10.1128/jvi.77.2.882-890.2003] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Virus-specific T-cell immune responses are important in restraint of human immunodeficiency virus type 1 (HIV-1) replication and control of disease. Plasma viral load is a key determinant of disease progression and infectiousness in HIV infection. Although HIV-1 subtype C (HIV-1C) is the predominant virus in the AIDS epidemic worldwide, the relationship between HIV-1C-specific T-cell immune responses and plasma viral load has not been elucidated. In the present study we address (i) the association between the level of plasma viral load and virus-specific immune responses to different HIV-1C proteins and their subregions and (ii) the specifics of correlation between plasma viral load and T-cell responses within the major histocompatibility complex (MHC) class I HLA supertypes. Virus-specific immune responses in the natural course of HIV-1C infection were analyzed in the gamma interferon (IFN-gamma)-enzyme-linked immunospot assay by using synthetic overlapping peptides corresponding to the HIV-1C consensus sequence. For Gag p24, a correlation was seen between better T-cell responses and lower plasma viral load. For Nef, an opposite trend was observed where a higher T-cell response was more likely to be associated with a higher viral load. At the level of the HLA supertypes, a lower viral load was associated with higher T-cell responses to Gag p24 within the HLA A2, A24, B27, and B58 supertypes, in contrast to the absence of such a correlation within the HLA B44 supertype. The present study demonstrated differential correlations (or trends to correlation) in various HIV-1C proteins, suggesting (i) an important role of the HIV-1C Gag p24-specific immune responses in control of viremia and (ii) more rapid viral escape from immune responses to Nef with no restraint of plasma viral load. Correlations between the level of IFN-gamma-secreting T cells and viral load within the MHC class I HLA supertypes should be considered in HIV vaccine design and efficacy trials.
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Novitsky V, Cao H, Rybak N, Gilbert P, McLane MF, Gaolekwe S, Peter T, Thior I, Ndung'u T, Marlink R, Lee TH, Essex M. Magnitude and frequency of cytotoxic T-lymphocyte responses: identification of immunodominant regions of human immunodeficiency virus type 1 subtype C. J Virol 2002; 76:10155-68. [PMID: 12239290 PMCID: PMC136554 DOI: 10.1128/jvi.76.20.10155-10168.2002] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2002] [Accepted: 06/27/2002] [Indexed: 11/20/2022] Open
Abstract
A systematic analysis of immune responses on a population level is critical for a human immunodeficiency virus type 1 (HIV-1) vaccine design. Our studies in Botswana on (i) molecular analysis of the HIV-1 subtype C (HIV-1C) epidemic, (ii) frequencies of major histocompatibility complex class I HLA types, and (iii) cytotoxic T-lymphocyte (CTL) responses in the course of natural infection allowed us to address HIV-1C-specific immune responses on a population level. We analyzed the magnitude and frequency of the gamma interferon ELISPOT-based CTL responses and translated them into normalized cumulative CTL responses. The introduction of population-based cumulative CTL responses reflected both (i) essentials of the predominant virus circulating locally in Botswana and (ii) specificities of the genetic background of the Botswana population, and it allowed the identification of immunodominant regions across the entire HIV-1C. The most robust and vigorous immune responses were found within the HIV-1C proteins Gag p24, Vpr, Tat, and Nef. In addition, moderately strong responses were scattered across Gag p24, Pol reverse transcriptase and integrase, Vif, Tat, Env gp120 and gp41, and Nef. Assuming that at least some of the immune responses are protective, these identified immunodominant regions could be utilized in designing an HIV vaccine candidate for the population of southern Africa. Targeting multiple immunodominant regions should improve the overall vaccine immunogenicity in the local population and minimize viral escape from immune recognition. Furthermore, the analysis of HIV-1C-specific immune responses on a population level represents a comprehensive systematic approach in HIV vaccine design and should be considered for other HIV-1 subtypes and/or different geographic areas.
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Novitsky V, Smith UR, Gilbert P, McLane MF, Chigwedere P, Williamson C, Ndung'u T, Klein I, Chang SY, Peter T, Thior I, Foley BT, Gaolekwe S, Rybak N, Gaseitsiwe S, Vannberg F, Marlink R, Lee TH, Essex M. Human immunodeficiency virus type 1 subtype C molecular phylogeny: consensus sequence for an AIDS vaccine design? J Virol 2002; 76:5435-51. [PMID: 11991972 PMCID: PMC137027 DOI: 10.1128/jvi.76.11.5435-5451.2002] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2001] [Accepted: 02/13/2002] [Indexed: 11/20/2022] Open
Abstract
An evolving dominance of human immunodeficiency virus type 1 subtype C (HIV-1C) in the AIDS epidemic has been associated with a high prevalence of HIV-1C infection in the southern African countries and with an expanding epidemic in India and China. Understanding the molecular phylogeny and genetic diversity of HIV-1C viruses may be important for the design and evaluation of an HIV vaccine for ultimate use in the developing world. In this study we analyzed the phylogenetic relationships (i) between 73 non-recombinant HIV-1C near-full-length genome sequences, including 51 isolates from Botswana; (ii) between HIV-1C consensus sequences that represent different geographic subsets; and (iii) between specific isolates and consensus sequences. Based on the phylogenetic analyses of 73 near-full-length genomes, 16 "lineages" (a term that is used hereafter for discussion purposes and does not imply taxonomic standing) were identified within HIV-1C. The lineages were supported by high bootstrap values in maximum-parsimony and neighbor-joining analyses and were confirmed by the maximum-likelihood method. The nucleotide diversity between the 73 HIV-1C isolates (mean value of 8.93%; range, 2.9 to 11.7%) was significantly higher than the diversity of the samples to the consensus sequence (mean value of 4.86%; range, 3.3 to 7.2%, P < 0.0001). The translated amino acid distances to the consensus sequence were significantly lower than distances between samples within all HIV-1C proteins. The consensus sequences of HIV-1C proteins accompanied by amino acid frequencies were presented (that of Gag is presented in this work; those of Pol, Vif, Vpr, Tat, Rev, Vpu, Env, and Nef are presented elsewhere [http://www.aids.harvard.edu/lab_research/concensus_sequence.htm]). Additionally, in the promoter region three NF-kappa B sites (GGGRNNYYCC) were identified within the consensus sequences of the entire set or any subset of HIV-1C isolates. This study suggests that the consensus sequence approach could overcome the high genetic diversity of HIV-1C and facilitate an AIDS vaccine design, particularly if the assumption that an HIV-1C antigen with a more extensive match to the circulating viruses is likely to be more efficacious is proven in efficacy trials.
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Kamal SM, Bianchi L, Al Tawil A, Koziel M, El Sayed Khalifa K, Peter T, Rasenack JW. Specific cellular immune response and cytokine patterns in patients coinfected with hepatitis C virus and Schistosoma mansoni. J Infect Dis 2001; 184:972-82. [PMID: 11574911 DOI: 10.1086/323352] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2001] [Indexed: 11/04/2022] Open
Abstract
Patients coinfected with hepatitis C virus (HCV) and Schistosoma mansoni show high incidence of viral persistence and accelerated fibrosis. To determine whether immunological mechanisms are responsible for this alteration in the natural history of HCV, the HCV-specific peripheral CD4(+) T cell responses and cytokines were analyzed in patients with chronic hepatitis C monoinfection, S. mansoni monoinfection, or HCV and S. mansoni coinfection. An HCV-specific CD4(+) proliferative response to at least 1 HCV antigen was detected in 73.3% of patients infected with HCV, compared with 8.6% of patients coinfected with HCV and S. mansoni. Stimulation with HCV antigens produced a type 1 cytokine profile in patients infected with HCV alone, compared with a type 2 predominance in patients coinfected with HCV and S. mansoni. In contrast, there was no difference in response to schistosomal antigens in patients infected with S. mansoni alone, compared with those coinfected with HCV and S. mansoni. These findings suggest that the inability to generate an HCV-specific CD4(+)/Th1 T cell response plays a role in the persistence and severity of HCV infection in patients with S. mansoni coinfection.
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Novitsky V, Rybak N, McLane MF, Gilbert P, Chigwedere P, Klein I, Gaolekwe S, Chang SY, Peter T, Thior I, Ndung'u T, Vannberg F, Foley BT, Marlink R, Lee TH, Essex M. Identification of human immunodeficiency virus type 1 subtype C Gag-, Tat-, Rev-, and Nef-specific elispot-based cytotoxic T-lymphocyte responses for AIDS vaccine design. J Virol 2001; 75:9210-28. [PMID: 11533184 PMCID: PMC114489 DOI: 10.1128/jvi.75.19.9210-9228.2001] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The most severe human immunodeficiency virus type 1 (HIV-1) epidemic is occurring in southern Africa. It is caused by HIV-1 subtype C (HIV-1C). In this study we present the identification and analysis of cumulative cytotoxic T-lymphocyte (CTL) responses in the southern African country of Botswana. CTLs were shown to be an important component of the immune response to control HIV-1 infection. The definition of optimal and dominant epitopes across the HIV-1C genome that are targeted by CTL is critical for vaccine design. The characteristics of the predominant virus that causes the HIV-1 epidemic in a certain geographic area and also the genetic background of the population, through the distribution of common HLA class I alleles, might impact dominant CTL responses in the vaccinee and in the general population. The enzyme-linked immunospot (Elispot) gamma interferon assay has recently been shown to be a reliable tool to map optimal CTL epitopes, correlating well with other methods, such as intracellular staining, tetramer staining, and the classical chromium release assay. Using Elispot with overlapping synthetic peptides across Gag, Tat, Rev, and Nef, we analyzed HIV-1C-specific CTL responses of HIV-1-infected blood donors. Profiles of cumulative Elispot-based CTL responses combined with diversity and sequence consensus data provide an additional characterization of immunodominant regions across the HIV-1C genome. Results of the study suggest that the construction of a poly-epitope subtype-specific HIV-1 vaccine that includes multiple copies of immunodominant CTL epitopes across the viral genome, derived from predominant HIV-1 viruses, might be a logical approach to the design of a vaccine against AIDS.
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Biele J, Tsias A, Luo BP, Carslaw KS, Neuber R, Beyerle G, Peter T. Nonequilibrium coexistence of solid and liquid particles in Arctic stratospheric clouds. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2001jd900188] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kamal SM, Rasenack JW, Bianchi L, Al Tawil A, El Sayed Khalifa K, Peter T, Mansour H, Ezzat W, Koziel M. Acute hepatitis C without and with schistosomiasis: correlation with hepatitis C-specific CD4(+) T-cell and cytokine response. Gastroenterology 2001; 121:646-56. [PMID: 11522749 DOI: 10.1053/gast.2001.27024] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Immune responses during the first few months of acute hepatitis C virus (HCV) infection seem crucial for viral control, but the relationship of these responses to natural history is poorly characterized. METHODS This prospective study investigated the HCV-specific CD4(+) and cytokine responses in patients with acute HCV hepatitis with or without Schistosoma mansoni coinfection, a parasitic infection with T helper (Th) 2 immune bias. HCV-specific CD4(+) proliferative responses and cytokine production in peripheral blood mononuclear cells were correlated with liver biopsy results at 6 months and at the end of follow-up. RESULTS Whereas 5 of 15 patients with HCV alone recovered from acute HCV, all (17 of 17) patients with S. mansoni coinfection progressed to histologically proven chronic hepatitis. Coinfected patients had either absent or transient weak HCV-specific CD4(+) responses with Th0/Th2 cytokine production. The magnitude of the HCV-specific CD4(+) response at week 12 was inversely correlated with the fibrosis progression rate in chronically infected patients. CONCLUSIONS Patients with acute hepatitis C and schistosomiasis coinfection cannot clear viremia and show rapid progression once chronic infection is established. This rapid progression is associated with a strong Th2 response in peripheral immune responses, suggesting that early development of vigorous Th1 responses not only facilitates clearance but delays disease progression.
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Fahey DW, Gao RS, Carslaw KS, Kettleborough J, Popp PJ, Northway MJ, Holecek JC, Ciciora SC, McLaughlin RJ, Thompson TL, Winkler RH, Baumgardner DG, Gandrud B, Wennberg PO, Dhaniyala S, McKinney K, Peter T, Salawitch RJ, Bui TP, Elkins JW, Webster CR, Atlas EL, Jost H, Wilson JC, Herman RL, Kleinböhl A, von König M. The detection of large HNO3-containing particles in the winter Arctic stratosphere. Science 2001; 291:1026-31. [PMID: 11161213 DOI: 10.1126/science.1057265] [Citation(s) in RCA: 231] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Large particles containing nitric acid (HNO3) were observed in the 1999/2000 Arctic winter stratosphere. These in situ observations were made over a large altitude range (16 to 21 kilometers) and horizontal extent (1800 kilometers) on several airborne sampling flights during a period of several weeks. With diameters of 10 to 20 micrometers, these sedimenting particles have significant potential to denitrify the lower stratosphere. A microphysical model of nitric acid trihydrate particles is able to simulate the growth and sedimentation of these large sizes in the lower stratosphere, but the nucleation process is not yet known. Accurate modeling of the formation of these large particles is essential for understanding Arctic denitrification and predicting future Arctic ozone abundances.
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Krieger UK, Mössinger JC, Luo B, Weers U, Peter T. Measurement of the Refractive Indices of H(2)SO(4)-HNO(3)-H(2)O Solutions to Stratospheric Temperatures. APPLIED OPTICS 2000; 39:3691-3703. [PMID: 18349944 DOI: 10.1364/ao.39.003691] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Refractive indices of various H(2)SO(4)-H(2)O, HNO(3)-H(2)O, and H(2)SO(4)-HNO(3)-H(2)O solutions were measured at four wavelengths in the visible (351.0, 533.5, 632.9, and 782.6 nm) over a temperature range from 30 to -60 degrees C. The temperature dependence has been determined for the first time to the authors' knowledge. This dependence is of importance for applications to atmospheric aerosols at low temperatures. In particular, it is shown that (1) the molar refractivity of the solutions is independent of temperature, whereas the temperature dependence of the refractive index arises solely through the temperature dependence of the solution's mass density, (2) the molar refractivities of H(2)SO(4) and HNO(3) in a ternary solution may be calculated as the weighted sum of the molar refractivities of two binary solutions evaluated at a concentration that corresponds to the total acid concentration, and (3) the H(2)O molar refractivity in the solutions may be taken equal to that of pure water. Although the data for the ternary system have been used for this model verification, data for binary H(2)SO(4)-H(2)O and HNO(3)-H(2)O solutions were used to improve the accuracy of the modeled refractive indices to better than 0.0017% or 0.15% for concentrations of 5-70 wt.% and wavelengths from the near ultraviolet to the near infrared (0.25-2 mum).
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Wirth M, Tsias A, Dörnbrack A, Weiß V, Carslaw KS, Leutbecher M, Renger W, Volkert H, Peter T. Model-guided Lagrangian observation and simulation of mountain polar stratospheric clouds. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1998jd100095] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Stefanutti L, MacKenzie AR, Balestri S, Khattatov V, Fiocco G, Kyrö E, Peter T. Airborne Polar Experiment-Polar Ozone, Leewaves, Chemistry, and Transport (APE-POLECAT): Rationale, road map and summary of measurements. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1998jd100078] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Tsias A, Wirth M, Carslaw KS, Biele J, Mehrtens H, Reichardt J, Wedekind C, Weiß V, Renger W, Neuber R, von Zahn U, Stein B, Santacesaria V, Stefanutti L, Fierli F, Bacmeister J, Peter T. Aircraft lidar observations of an enhanced type Ia polar stratospheric clouds during APE-POLECAT. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1998jd100055] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Waibel AE, Peter T, Carslaw KS, Oelhaf H, Wetzel G, Crutzen PJ, Poschl U, Tsias A, Reimer E, Fischer H. Arctic ozone loss due to denitrification. Science 1999; 283:2064-9. [PMID: 10092225 DOI: 10.1126/science.283.5410.2064] [Citation(s) in RCA: 176] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Measurements from the winter of 1994-95 indicating removal of total reactive nitrogen from the Arctic stratosphere by particle sedimentation were used to constrain a microphysical model. The model suggests that denitrification is caused predominantly by nitric acid trihydrate particles in small number densities. The denitrification is shown to increase Arctic ozone loss substantially. Sensitivity studies indicate that the Arctic stratosphere is currently at a threshold of denitrification. This implies that future stratospheric cooling, induced by an increase in the anthropogenic carbon dioxide burden, is likely to enhance denitrification and to delay until late in the next century the return of Arctic stratospheric ozone to preindustrial values.
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