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Barnard EB, Smith JE, Manning JE, Rall JM, Cox JM, Bebarta VS, Ross JD. A DESCRIPTIVE PARADIGM OF ESCALATING ENDOVASCULAR INTERVENTION FOR THE MANAGEMENT OF TRAUMATIC CARDIAC ARREST IN A SWINE MODEL OF NON-COMPRESSIBLE TORSO HAEMORRHAGE. Arch Emerg Med 2016. [DOI: 10.1136/emermed-2016-206402.5] [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: 11/03/2022]
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Barnard EB, Smith JE, Manning JE, Rall JM, Cox JM, Bebarta VS, Ross JD. SELECTIVE AORTIC ARCH PERFUSION FOR THE REVERSAL OF HAEMORRHAGE-INDUCED TRAUMATIC CARDIAC ARREST IN A SWINE MODEL OF NON-COMPRESSIBLE TORSO HAEMORRHAGE. Arch Emerg Med 2016. [DOI: 10.1136/emermed-2016-206402.1] [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: 11/04/2022]
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Manning JE. Transpulmonary Thermodilution Cardiac Output and Pulse Contour Analysis Continuous Cardiac Output in a Swine Model of Severe Hemorrhagic Shock: Comparison with Pulmonary Artery Cardiac Output. Acad Emerg Med 2004. [DOI: 10.1197/j.aem.2004.02.069] [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]
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Manning JE, Katz LM, Pearce LB, Batson DN, McCurdy SL, Gawryl MS, Baker CC. Selective aortic arch perfusion with hemoglobin-based oxygen carrier-201 for resuscitation from exsanguinating cardiac arrest in swine. Crit Care Med 2001; 29:2067-74. [PMID: 11700396 DOI: 10.1097/00003246-200111000-00005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The prospects for resuscitation after blunt traumatic cardiac arrest are dismal. Selective aortic arch perfusion (SAAP) with a hemoglobin-based oxygen carrier (HBOC-201) offers a potentially effective therapy. This study evaluated the acute cardiovascular and metabolic effects of SAAP with HBOC-201 in an exsanguination model of cardiac arrest. DESIGN Randomized, controlled, laboratory investigation. SETTING University research laboratory. SUBJECTS Domestic swine, 25-39 kg. INTERVENTIONS Partial resection of four liver lobes rapidly led to profound hemorrhagic shock and subsequent cardiac arrest at 10-13 mins. At 15 mins, swine were randomized to receive either SAAP with oxygenated lactated Ringer's (LR) solution (n = 6) or SAAP with oxygenated HBOC-201 (n = 6) at a rate of 10 mL x kg(-1) x min(-1) until return of spontaneous circulation with a mean aortic pressure of 60 mm Hg (8.0 kPa) was achieved. Epinephrine (0.005 mg/kg) was given via intra-aortic route every 30 secs as needed to promote return of spontaneous circulation beginning at 18 mins after onset of liver injury (3 mins after beginning SAAP). MEASUREMENTS AND MAIN RESULTS Mean aortic pressure, cardiac output, total blood loss, and time of arrest were similar for both groups before SAAP therapy. In the SAAP-HBOC group, return of spontaneous circulation with a sustained mean aortic pressure of 60 mm Hg (8.0 kPa) was achieved in six of six swine at 1.9 +/- 0.3 mins of SAAP, and none of these swine required epinephrine. In the SAAP-LR group, no swine (from a total of six) achieved return of spontaneous circulation before intra-aortic epinephrine administration, and only two of six swine had brief return of spontaneous circulation with an mean aortic pressure of 60 mm Hg (8.0 kPa) after intra-aortic epinephrine that was sustained for <10 mins. One-hour survival was five of six in the SAAP-HBOC group and none of six in the SAAP-LR group (p <.05, Fisher's exact test). CONCLUSION SAAP with oxygenated HBOC-201 rapidly restored viable cardiovascular function after exsanguinating cardiac arrest in this swine model of liver injury with profound hemorrhagic shock.
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Affiliation(s)
- J E Manning
- Department of Emergency Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7594, USA.
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Yoshikawa H, Matsubara K, Qian GS, Jackson P, Groopman JD, Manning JE, Harris CC, Herman JG. SOCS-1, a negative regulator of the JAK/STAT pathway, is silenced by methylation in human hepatocellular carcinoma and shows growth-suppression activity. Nat Genet 2001; 28:29-35. [PMID: 11326271 DOI: 10.1038/ng0501-29] [Citation(s) in RCA: 430] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hepatocellular carcinoma (HCC) is a major cause of cancer death, but the molecular mechanism for its development beyond its initiation has not been well characterized. Suppressor of cytokine signaling (SOCS-1; also known as JAB and SSI-1) switches cytokine signaling 'off' by means of its direct interaction with Janus kinase (JAK). We identified aberrant methylation in the CpG island of SOCS-1 that correlated with its transcription silencing in HCC cell lines. The incidence of aberrant methylation was 65% in the 26 human primary HCC tumor samples analyzed. Moreover, the restoration of SOCS-1 suppressed both growth rate and anchorage-independent growth of cells in which SOCS-1 was methylation-silenced and JAK2 was constitutively activated. This growth suppression was caused by apoptosis and was reproduced by AG490, a specific, chemical JAK2 inhibitor that reversed constitutive phosphorylation of STAT3 in SOCS-1 inactivated cells. The high prevalence of the aberrant SOCS-1 methylation and its growth suppression activity demonstrated the importance of the constitutive activation of the JAK/STAT pathway in the development of HCC. Our results also indicate therapeutic strategies for the treatment of HCC including use of SOCS-1 in gene therapy and inhibition of JAK2 by small molecules, such as AG490.
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Affiliation(s)
- H Yoshikawa
- The Johns Hopkins University School of Medicine, The Oncology Center, Baltimore, Maryland, USA
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de Diego JL, Katz JM, Marshall P, Gutiérrez B, Manning JE, Nussenzweig V, González J. The ubiquitin-proteasome pathway plays an essential role in proteolysis during Trypanosoma cruzi remodeling. Biochemistry 2001; 40:1053-62. [PMID: 11170428 DOI: 10.1021/bi001659k] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Here, we document for the first time the presence of the 26S proteasome and the ubiquitin pathway in a protozoan parasite that is in an early branch in the eukaryotic lineage. The 26S proteasome of Trypanosoma cruzi epimastigotes was identified as a high molecular weight complex (1400 kDa) with an ATP-dependent chymotrypsin-like activity against the substrate Suc-LLVY-Amc. This activity was inhibited by proteasome inhibitors and showed same electrophorectic migration pattern as yeast 26S proteasome in nondenaturating gels. About 30 proteins in a range of 25-110 kDa were detected in the purified T. cruzi 26S proteasome. Antibodies raised against the AAA family of ATPases from eukaryotic 26S proteasome and the T. cruzi 20S core specifically recognized components of T. cruzi 26S. To confirm the biological role of 26S in this primitive eukaryotic parasite, we analyzed the participation of the ubiquitin (Ub)-proteasome system in protein degradation during the time of parasite remodeling. Protein turnover in trypomastigotes was proteasome and ATP-dependent and was enhanced during the transformation of the parasites into amastigotes. If 20S proteasome activity is inhibited, ubiquitinated proteins accumulate in the parasites. As expected from the profound morphological changes that occur during transformation, cytoskeletal proteins associated with the flagellum are targets of the ubiquitin-proteasome pathway.
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Affiliation(s)
- J L de Diego
- Michael Heidelberger Division, Pathology Department, New York University School of Medicine, New York, New York 10016, USA.
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Abstract
The future of cardiopulmonary resuscitation lies in new technologies for monitoring and generating vital organ perfusion during cardiac arrest and the post-resuscitation phase and in pharmacologic agents that will enhance ROSC and reverse ischemia-reperfusion injury. ROSC is the first step toward survival, so interventions that improve ROSC deserve further investigation. Long-term survival with good neurologic recovery is the critical endpoint. Interventions recommended for clinical practice must therefore demonstrate improved long-term survival. The resources required to provide many of the interventions discussed in this article, principally invasive perfusion technologies, cannot be justified unless there is clear benefit. The allocation of such resources to provide intensive resuscitation and post-resuscitation support will need to be addressed from medical and societal viewpoints.
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Affiliation(s)
- J E Manning
- Department of Emergency Medicine, University of North Carolina School of Medicine, Chapel Hill, USA.
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Manning JE, Katz LM, Brownstein MR, Pearce LB, Gawryl MS, Baker CC. Bovine hemoglobin-based oxygen carrier (HBOC-201) for resuscitation of uncontrolled, exsanguinating liver injury in swine. Carolina Resuscitation Research Group. Shock 2000; 13:152-9. [PMID: 10670846 DOI: 10.1097/00024382-200013020-00010] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In the setting of rapidly exsanguinating hemorrhage, resuscitation with intravenous (i.v.) crystalloid solution may not sustain survival before availability of allogenic blood transfusion and surgery. This study tested the hypothesis that bovine hemoglobin-based oxygen carrier, HBOC-201, would improve resuscitation and extend early survival from exsanguinating hemorrhage. This study simulated the prehospital scenario of rapidly exsanguinating hemorrhage with prolonged prehospital time and lack of blood availability. Severe hemorrhagic shock was induced in swine by using multiple liver lacerations. At 9 min after the onset of bleeding, swine were randomized to receive approximately 10 mL/kg/min of i.v. lactated Ringer's solution (n = 10) or HBOC-201 (n = 7) to achieve a mean aortic pressure (MAP) of 60 mmHg. Thereafter, infusion rate was adjusted to maintain MAP at 60 mmHg for up to 2 h. All animals were initially successfully resuscitated. The results showed 2-h survival was 1 of 10 with lactated Ringer's and 7 of 7 with HBOC-201 (P = 0.0004). Nine lactated Ringer's swine had cardiovascular collapse at 36 +/- 10 min. Lactate at 30 min was 18 +/- 3 mmol/L with lactated Ringer's and 12 +/- 2 mmol/L with HBOC-201 (P < 0.05). Hematocrit was <1% in 9 of 10 lactated Ringer's and 6 of 7 HBOC-201 animals. These data indicate that HBOC-201 improved early survival and stabilized hemodynamic and metabolic parameters vs. lactated Ringer's in this swine model of liver injury with uncontrolled, lethal hemorrhage that simulates the prehospital care environment where allogenic blood is unavailable.
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Affiliation(s)
- J E Manning
- Department of Emergency Medicine, School of Medicine, University of North Carolina at Chapel Hill, 27599-7594, USA
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Wrightsman RA, Manning JE. Paraflagellar rod proteins administered with alum and IL-12 or recombinant adenovirus expressing IL-12 generates antigen-specific responses and protective immunity in mice against Trypanosoma cruzi. Vaccine 2000; 18:1419-27. [PMID: 10618540 DOI: 10.1016/s0264-410x(99)00380-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Successful vaccination of mice against an otherwise lethal challenge with the Peru strain of Trypanosoma cruzi necessitates the induction of a strong cell mediated immune response. Previously, immunization of mice with the paraflagellar rod proteins from Trypanosoma cruzi90% reduction in parasitemia in immunized mice challenged with the bloodstream stage of Trypanosoma cruzi.
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Affiliation(s)
- R A Wrightsman
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92696-3900, USA
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Quanquin NM, Galaviz C, Fouts DL, Wrightsman RA, Manning JE. Immunization of mice with a TolA-like surface protein of Trypanosoma cruzi generates CD4(+) T-cell-dependent parasiticidal activity. Infect Immun 1999; 67:4603-12. [PMID: 10456906 PMCID: PMC96784 DOI: 10.1128/iai.67.9.4603-4612.1999] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The gene family encoding a trypomastigote-specific protein restricted to the part of the flagellum in contact with the cell body of the trypomastigote form of Trypanosoma cruzi has been isolated, characterized, and expressed in a baculovirus expression system. The gene family contains three tandemly repeated members that have 97 to 100% sequence identity. The predicted protein encoded by the gene family has both significant amino acid sequence identity and other physical and biological features in common with the TolA proteins of Escherichia coli and Pseudomonas aeruginosa. Based on these similarities, we have designated this gene family tolT. Immunization of mice with recombinant TolT generates a population of CD4(+) T lymphocytes that recognize T. cruzi-infected macrophages, resulting in the production of gamma interferon (IFN-gamma), which leads to NO production and a 50 to 60% reduction in parasite numbers compared to that seen with infected macrophages incubated with naive T cells. This population of T cells also produces both IFN-gamma and interleukin 2 (IL-2) but not IL-4 or IL-5 when incubated with spleen cells stimulated with TolT antigen, indicating that they are of the T-helper 1 type. T cells from mice chronically infected with T. cruzi also produce significant levels of IFN-gamma when cocultured with macrophages and either TolT protein or paraflagellar rod protein, indicating that both of these flagellar proteins produce positive T-cell responses in mice chronically infected with T. cruzi.
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Affiliation(s)
- N M Quanquin
- Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697-3900, USA
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Giordano R, Fouts DL, Tewari D, Colli W, Manning JE, Alves MJ. Cloning of a surface membrane glycoprotein specific for the infective form of Trypanosoma cruzi having adhesive properties to laminin. J Biol Chem 1999; 274:3461-8. [PMID: 9920891 DOI: 10.1074/jbc.274.6.3461] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Trypomastigotes of Trypanosoma cruzi express a set of surface glycoproteins known, collectively, as Tc-85. A monoclonal antibody to these proteins, named H1A10, inhibits (50-90%) in vitro parasite interiorization into host cells, thus implicating these glycoproteins in the infection process. Two DNA inserts, a genomic DNA fragment and a full-length cDNA encoding the H1A10 epitope, have now been cloned and characterized. Results show that both have high sequence identity with all reported members of the gp85/trans-sialidase gene family, although the H1A10 epitope exists only in the Tc-85 subset of the family. The epitope has been mapped by competition of antibody binding to a Tc-85 recombinant protein with peptides having sequences predicted by the Tc-85 DNA sequence, which contains also putative N-glycosylation sites and COOH-terminal glycosylphosphatidylinositol anchor insertion sites, as expected, since an N-glycan chain and a glycosylphosphatidylinositol anchor have been characterized previously in the Tc-85 subset. The protein encoded by the full-length cDNA insert binds to cells and in vitro to laminin, but not to gelatin or fibronectin, in a saturable manner. For the first time it was possible to assign a defined ligand to a sequenced glycoprotein belonging to the gp85 family. This fact, together with the reported binding of family members to cell surfaces, reinforces the hypothesis that this family encodes glycoproteins with similar sequences but differing enough as to bind to different ligands and thus forming a family of adhesion glycoproteins enabling the parasite to overcome the barriers interposed by cell membranes, extracellular matrices, and basal laminae.
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Affiliation(s)
- R Giordano
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Caixa Postal 26077, São Paulo 05599-970, S. P., Brazil
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Fouts DL, Stryker GA, Gorski KS, Miller MJ, Nguyen TV, Wrightsman RA, Manning JE. Evidence for four distinct major protein components in the paraflagellar rod of Trypanosoma cruzi. J Biol Chem 1998; 273:21846-55. [PMID: 9705323 DOI: 10.1074/jbc.273.34.21846] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The major structural proteins present in the paraflagellar rod of Trypanosoma cruzi migrate on SDS-polyacrylamide gels as two distinct electrophoretic bands. The gene encoding a protein present in the faster migrating band, designated PAR 2, has been identified previously. Here we report the isolation and partial characterization of three genes, designated par 1, par 3, and par 4, that encode proteins present in the two paraflagellar rod protein bands. Peptide-specific polyclonal antibodies and monoclonal antibodies against the four proteins encoded by these genes shows that PAR 1 and PAR 3 are present only in the slower migrating paraflagellar rod band, and that PAR 2 and PAR 4 are present only in the faster migrating band. Analysis of the nucleotide sequence of these genes and the amino acid sequence of the conceptual proteins encoded by them indicates that par 2 shares high sequence similarity with par 3 and both are members of a common gene family, of which par 1 may be a distant member. Analysis of gene copy number and steady-state RNA levels suggest that the close stoichiometric ratio of the four PAR proteins is likely maintained by homeostatic regulation of RNA levels rather than gene dosage.
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Affiliation(s)
- D L Fouts
- Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697-3900, USA
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Manning JE, Ragavendra N, Sayre J, Laifer-Narin SL, Melany ML, Grant EG, Crandall BF. Significance of fetal intracardiac echogenic foci in relation to trisomy 21: a prospective sonographic study of high-risk pregnant women. AJR Am J Roentgenol 1998; 170:1083-4. [PMID: 9530064 DOI: 10.2214/ajr.170.4.9530064] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE The aim of the study was to determine if an association exists between intracardiac echogenic foci in the second-trimester fetus and trisomy 21. SUBJECTS AND METHODS Over a 2-year period, targeted fetal sonography was performed for various indications in 1593 second-trimester high-risk pregnant women. Presence or absence of echogenic foci was recorded for each fetus. Amniocentesis for karyotype analysis was performed in 901 subjects immediately after sonography. The findings of these 901 subjects formed the basis of this report. RESULTS Intracardiac echogenic foci were present in the left ventricle of 24 (3%) of the 901 fetuses. Three (13%) of these 24 fetuses had trisomy 21; no chromosomal abnormalities were found in the other 21 fetuses. Karyotype analysis revealed trisomy 21 in 14 (2%) of the remaining 877 fetuses who did not exhibit intracardiac echogenic foci. The sensitivity, specificity, positive predictive values, and negative predictive values for intracardiac echogenic foci in predicting trisomy 21 were 18%, 98%, 13%, and 98%, respectively. The association of intracardiac echogenic foci and trisomy 21 was significant (p < .009) by the two-tailed Fisher's exact test. CONCLUSION In a high-risk obstetric population, the association between fetal intracardiac echogenic foci and trisomy 21 was statistically significant. Therefore, women carrying fetuses with intracardiac echogenic foci should be informed of the statistical association with trisomy 21.
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Affiliation(s)
- J E Manning
- Department of Radiological Sciences, UCLA School of Medicine 90095-6969, USA
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Affiliation(s)
- J E Manning
- Department of Radiological Sciences, UCLA School of Medicine, Los Angeles, California 90024-1721, USA
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Abstract
OBJECTIVE To determine whether selective aortic arch perfusion (SAAP) using serial infusions of oxygenated perflubron emulsion combined with aortic epinephrine (AoE) administration is more effective than conventional therapy in treating cardiac arrest. METHODS An experimental cardiac arrest model (10 min ventricular fibrillation and 2 min CPR) was used with 12 mixed-breed canines, randomized into 2 groups: control (n = 6), CPR and IV epinephrine, 0.01 mg/kg, at 12 min and then every 3 min; or AoE-SAAP (n = 6), CPR and aortic epinephrine, 0.01 mg/kg, at 12 min and then every 3 min, and serial SAAP with oxygenated 60% weight/volume (w/v) perflubron emulsion as follows: 300 mL over 30 sec at 12 min as continuous SAAP without CPR; 150 mL over 20-30 sec at 15 min and 18 min as pulsed diastolic SAAP during CPR. RESULTS AoE-SAAP resulted in increased coronary perfusion pressure (CPP) and return of spontaneous circulation (ROSC) compared with control. CPR-diastolic (release phase) CPP during pulsed diastolic SAAP was similar to or greater in magnitude than the CPP generated during the initial SAAP infusion without CPR. ROSC for control was 0/6 and for AoE-SAAP was 4/6 (p < 0.05, Fisher's exact test). Time from initiation of CPR to ROSC with a sustained systolic aortic pressure > 60 mm Hg was 8.0 +/- 1.2 min in the 4 resuscitated AoE-SAAP animals. CONCLUSION The combination of AoE with SAAP infusions of oxygenated perflubron emulsion was more effective than conventional resuscitation therapy. Pulsed diastolic SAAP is a promising method for performing SAAP.
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Affiliation(s)
- J E Manning
- Department of Emergency Medicine, University of North Carolina School of Medicine, Chapel Hill 27599, USA.
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Manning JE. Research in emergency medicine. N C Med J 1997; 58:296-9. [PMID: 9233052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- J E Manning
- Department of Emergency Medicine, University of North Carolina School of Medicine, Chapel Hill 27599, USA
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Miller MJ, Wrightsman RA, Stryker GA, Manning JE. Protection of mice against Trypanosoma cruzi by immunization with paraflagellar rod proteins requires T cell, but not B cell, function. The Journal of Immunology 1997. [DOI: 10.4049/jimmunol.158.11.5330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Previous studies have shown that immunization of mice with the paraflagellar rod proteins (PAR) of Trypanosoma cruzi induces an immune response capable of protecting mice against an otherwise lethal challenge with this parasite. Herein, we define immunologic responses that do or do not play a critical role in PAR-mediated protection. Firstly, PAR-immunized Ab-deficient (muMT) strain mice survived an otherwise lethal T. cruzi challenge, indicating that a B cell response is not required for PAR-induced immunity. However, beta2m -/- mice, which are severely deficient in MHC class I and TCR alphabeta+ CD8+ CD4- T cells, did not survive challenge infection following PAR immunization, indicating that MHC class I/CD8+ T cell function is necessary for protection induced by PAR immunization. Surprisingly, PAR-immunized mice depleted of CD4+ T cells survived a T. cruzi challenge for >84 days postinfection while maintaining a parasitemia that is generally thought to be lethal (i.e., >10(6) trypomastigotes/ml), thus associating CD4+ T cell function with the process of parasite clearance. Consistent with this association, CD4+ T cells from PAR-immunized mice released INF-gamma and stimulated T. cruzi-infected macrophages to release nitric oxide. The importance of IFN-gamma in PAR-induced protective immunity is further indicated by the observation that PAR-immunized INF-gamma knockout mice developed an extremely high parasitemia and did not survive a challenge infection. Thus, while Ab-mediated immune mechanisms are not required for protection induced by PAR immunization, T cell responses are necessary for both elimination of bloodstream parasites and survival.
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Affiliation(s)
- M J Miller
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92697, USA
| | - R A Wrightsman
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92697, USA
| | - G A Stryker
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92697, USA
| | - J E Manning
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92697, USA
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Miller MJ, Wrightsman RA, Stryker GA, Manning JE. Protection of mice against Trypanosoma cruzi by immunization with paraflagellar rod proteins requires T cell, but not B cell, function. J Immunol 1997; 158:5330-7. [PMID: 9164953] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Previous studies have shown that immunization of mice with the paraflagellar rod proteins (PAR) of Trypanosoma cruzi induces an immune response capable of protecting mice against an otherwise lethal challenge with this parasite. Herein, we define immunologic responses that do or do not play a critical role in PAR-mediated protection. Firstly, PAR-immunized Ab-deficient (muMT) strain mice survived an otherwise lethal T. cruzi challenge, indicating that a B cell response is not required for PAR-induced immunity. However, beta2m -/- mice, which are severely deficient in MHC class I and TCR alphabeta+ CD8+ CD4- T cells, did not survive challenge infection following PAR immunization, indicating that MHC class I/CD8+ T cell function is necessary for protection induced by PAR immunization. Surprisingly, PAR-immunized mice depleted of CD4+ T cells survived a T. cruzi challenge for >84 days postinfection while maintaining a parasitemia that is generally thought to be lethal (i.e., >10(6) trypomastigotes/ml), thus associating CD4+ T cell function with the process of parasite clearance. Consistent with this association, CD4+ T cells from PAR-immunized mice released INF-gamma and stimulated T. cruzi-infected macrophages to release nitric oxide. The importance of IFN-gamma in PAR-induced protective immunity is further indicated by the observation that PAR-immunized INF-gamma knockout mice developed an extremely high parasitemia and did not survive a challenge infection. Thus, while Ab-mediated immune mechanisms are not required for protection induced by PAR immunization, T cell responses are necessary for both elimination of bloodstream parasites and survival.
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Affiliation(s)
- M J Miller
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92697, USA
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Manning JE, Batson DN, Payne FB, Adam N, Murphy CA, Perretta SG, Norfleet EA. Selective aortic arch perfusion during cardiac arrest: enhanced resuscitation using oxygenated perflubron emulsion, with and without aortic arch epinephrine. Ann Emerg Med 1997; 29:580-7. [PMID: 9140240 DOI: 10.1016/s0196-0644(97)70244-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
STUDY OBJECTIVE To evaluate selective aortic arch perfusion (SAAP) with an oxygenated fluorocarbon emulsion, with and without aortic arch epinephrine during cardiac arrest. METHODS This randomized, controlled study, undertaken at a university research laboratory, involved 15 mixed-breed dogs. After 10 minutes of ventricular fibrillation and 30 seconds of CPR, the dogs were randomized to three groups, each comprising five dogs. Group 1 (controls) dogs were given CPR and intravenous epinephrine, .01 mg/kg, at 10.5 minutes and then every 3 minutes. Group 2 dogs (IVE-SAAP) were treated with CPR and intravenous epinephrine (IVE) in the same fashion as the control group but were also subjected to SAAP with 275 mL of oxygenated 60% wt/vol perflubron emulsion over 30 seconds. Group 3 dogs (AoE-SAAP) received the same treatment as the IVE-SAAP group, except that the first epinephrine dose was given intraaortically. RESULTS Coronary perfusion pressure (CPP) increased during SAAP in both the IVE-SAAP and AoE-SAAP groups but was greater in the AoE-SAAP group. CPR diastolic CPP after SAAP was significantly greater in the AoE-SAAP group than in the control group. Return of spontaneous circulation (ROSC) occurred in two control dogs, all five IVE-SAAP dogs, and all five AoE-SAAP dogs. The time elapsed from the initiation of CPR to ROSC was 6.1 +/- 1.9 minutes in the AoE-SAAP group, compared with 11.0 +/- 5.8 minutes in the IVE-SAAP group. CONCLUSION SAAP with oxygenated perflubron emulsion improved ROSC, both with and without aortic arch epinephrine. The combination of SAAP with perflubron emulsion and aortic arch epinephrine resulted in higher CPP and more rapid ROSC.
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Affiliation(s)
- J E Manning
- Department of Emergency Medicine, School of Medicine, University of North Carolina, Chapel Hill, USA.
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20
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Beddingfield FC, Garrison HG, Manning JE, Lewis RJ. Factors associated with prolongation of transport times of emergency pediatric patients requiring transfer to a tertiary care center. Pediatr Emerg Care 1996; 12:416-9. [PMID: 8989788 DOI: 10.1097/00006565-199612000-00007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE The purpose of this study was to determine factors associated with longer times to transport of emergency pediatric patients requiring tertiary care. DESIGN Retrospective case series. SETTING Emergency pediatric transport service. PARTICIPANTS Infants and children transported by the transport service at the University of North Carolina Hospitals at Chapel Hill from January 1, 1988, to December 31, 1990. MAIN MEASUREMENTS The time-to-request, the time from patient arrival at the referring hospital to the time when the request for transfer was received, and the ground time, defined as the time between the transport team's arrival at the referring hospital and their departure, were recorded for each transported patient. RESULTS Three hundred consecutive children 0 to 16 years (61% male) were transferred. Time-to-request was shorter for trauma patients (median 62 minutes, quartiles 29 and 153 minutes) than for medical patients (median 172 minutes, quartiles 83 and 508 minutes) (P = 0.0001). Infants, children, and adolescents had similar times-to-request of 147 minutes, 129 minutes, and 128 minutes, respectively (P = 0.91). Increased ground times were associated with diagnosis category (median of 40 minutes for medical patients vs 29 minutes for trauma patients) (P = 0.0001), with younger age (median of 46 minutes for infants, 35 minutes for children, and 28 minutes for adolescents) (P = 0.0001), and with the performance of major procedures (median of 35 minutes if no procedures were performed, 38 minutes if one procedure was performed, and 54 minutes if two procedures were performed) (P = 0.039). After the transport team arrived, 13% (40/300) of patients required at least one major procedure prior to transport. CONCLUSIONS Increased time-to-request for patients with medical diagnoses, increased ground times for younger patients and patients with medical diagnoses, and failure to perform necessary procedures contribute to a prolongation of the time-to-transport of emergency pediatric patients. The magnitude of the impact of these longer transport times on outcome is unknown.
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Affiliation(s)
- F C Beddingfield
- Department of Emergency Medicine, Harbor-UCLA Medical Center, Torrance 90509-2910
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Miller MJ, Wrightsman RA, Manning JE. Trypanosoma cruzi: protective immunity in mice immunized with paraflagellar rod proteins is associated with a T-helper type 1 response. Exp Parasitol 1996; 84:156-67. [PMID: 8932765 DOI: 10.1006/expr.1996.0101] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We have examined the ability of mice to survive a lethal challenge with the parasitic hemoflagellate, Trypanosoma cruzi, following immunization with paraflagellar rod proteins (PAR) 1 and 2 either alone or in combination with the following adjuvants: Freund's, alum, QS-21, Ribi-700, or IL-12. PAR administered subcutaneously (sc) in combination with Freund's or alum provided significant protection, 100 and 83%, respectively, against a T. cruzi challenge. In contrast, PAR in combination with QS-21, Ribi-700, IL-12, or Freund's administered intraperitoneally (ip) or PAR alone provide no protection against a challenge. PAR-specific serum antibody titers and isotype profiles for several of the immunization regimens were determined, and no positive correlation could be seen between a protective immune response and either antibody titer or the subclass of antibody induced. We also examined the ability of PAR to stimulate T cells from the spleen and lymph nodes of mice immunized with PAR in combination with Freund's (sc), Freund's (ip), alum, or Ribi-700. Each of the adjuvants strongly enhanced the ability of enriched T cells to proliferate in a PAR-specific fashion, suggesting no obvious correlation between PAR-specific T cell activation and protection. However, examination of the cytokine profiles of the stimulated T cell groups showed that the protective groups differed from the nonprotective groups. While all four groups showed low levels of IL-10, the Freund's (sc) and alum groups had higher levels of IFN-gamma and IL-2 than Freund's (ip) and Ribi-700 groups, and most strikingly, no IL-4 could be detected in either the Freund's (sc) or the alum group, in contrast to significant levels of IL-4 in both the Freund's (ip) and the Ribi-700 group. These findings indicate that protective immunity in mice immunized with PAR is associated with a Th1-type response.
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Affiliation(s)
- M J Miller
- Department of Molecular Biology and Biochemistry, University of California at Irvine 92697, USA
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Barton C, Manning JE, Batson N. Effect of selective aortic arch perfusion on median frequency and peak amplitude of ventricular fibrillation in a canine model. Ann Emerg Med 1996; 27:610-6. [PMID: 8629783 DOI: 10.1016/s0196-0644(96)70165-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY OBJECTIVE To determine whether the computer-derived measures of median frequency or peak amplitude of ventricular fibrillation (VF), obtained by fast Fourier transform of the VF waveform, change during selective aortic arch perfusion in a canine model of cardiac arrest. METHODS Eight mongrel dogs (including 4 control animals) were sedated, intubated, catheterized, and instrumented to record the electrocardiogram (digitally at 100 Hz, filtered with a finite impulse response filter at 2 Hz), right atrial pressure, and aortic pressure during resuscitation in a model of VF-induced cardiac arrest. After 10 minutes of VF-induced arrest, cardiopulmonary resuscitation (CPR) with a mechanical chest compression device was initiated. Beginning 2 minutes later, the 4 study animals received, every 2 minutes, 45 seconds of selective aortic arch perfusion (SAAP) with autologous blood infusions under high pressure. Defibrillation was attempted after 3 minutes of CPR and every minute thereafter. Both study and control groups received standard-dose epinephrine (.01 mg/kg) every 3 minutes by means of an intraaortic catheter. The median frequency, peak amplitude, and coronary perfusion pressure (CPP) during the 5-second period just before defibrillation were obtained with the use of computer algorithms. RESULTS All SAAP animals and 1 control animal were resuscitated. Baseline measures of median frequency (8.4 +/- 1.5 versus 6.6 +/- 1.0 Hz) and peak amplitude (.18 +/- .05 versus .36 +/- .13 mV) were not different between the SAAP and control groups, respectively, at the start of CRP. SAAP infusion resulted in significant increases in the SAAP group compared with the control group: median frequency, 9.6 +/- .4 versus 7.3 +/- 1.4 Hz; peak amplitude, .74 +/- .21 versus .39 +/- .15 mV; and CPP, 40.5 +/- 7.1 versus 18.0 +/- 15.0 mm Hg, respectively. Median frequency correlated with CPP (r2 = .67). Peak amplitude did not correlate with CPP (r2 = .06). CONCLUSION Median frequency and peak amplitude increase with SAAP during cardiac arrest in a canine model. This method of resuscitation was reliable in allowing restoration of a stable perfusing rhythm after defibrillation. Changes in measures of peak amplitude and median frequency may reflect interventions that enhance the likelihood of successful defibrillation and may thereby offer a noninvasive means of monitoring interventions during cardiac arrest.
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Affiliation(s)
- C Barton
- Department of Emergency Medicine, University of North Carolina-Chapel Hill, USA
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Barton CW, Manning JE. Cardiopulmonary resuscitation. Emerg Med Clin North Am 1995; 13:811-29. [PMID: 7588191] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Research into the physiologic changes that occur during cardiac arrest and resuscitation have led to important changes in our approach to resuscitation of the cardiac arrest victim. Methods that improve coronary perfusion pressure, coupled with direct or indirect measures of coronary perfusion, are actively being sought to improve resuscitation rates and outcomes. These studies have broadened the therapeutic options available to clinicians treating the cardiac arrest victim. Although significant improvements in hospital discharge rates and neurologic outcome have not been realized as yet, a firm basis for future studies has been established. Overall, the most significant intervention that the clinician can presently perform is early and prompt defibrillation of the patient in ventricular fibrillation.
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Affiliation(s)
- C W Barton
- Department of Emergency Medicine, University of North Carolina at Chapel Hill School of Medicine, USA
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Zhou S, Yang Y, Scott MJ, Pannuti A, Fehr KC, Eisen A, Koonin EV, Fouts DL, Wrightsman R, Manning JE. Male-specific lethal 2, a dosage compensation gene of Drosophila, undergoes sex-specific regulation and encodes a protein with a RING finger and a metallothionein-like cysteine cluster. EMBO J 1995; 14:2884-95. [PMID: 7796814 PMCID: PMC398407 DOI: 10.1002/j.1460-2075.1995.tb07288.x] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In Drosophila the equalization of X-linked gene products between males and females, i.e. dosage compensation, is the result of a 2-fold hypertranscription of most of these genes in males. At least four regulatory genes are required for this process. Three of these genes, maleless (mle), male-specific lethal 1 (msl-1) and male-specific lethal 3 (msl-3), have been cloned and their products have been shown to interact and to bind to numerous sites on the X chromosome of males, but not of females. Although binding to the X chromosome is negatively correlated with the function of the master regulatory gene Sex lethal (Sxl), the mechanisms that restrict this binding to males and to the X chromosome are not yet understood. We have cloned the last of the known autosomal genes involved in dosage compensation, male-specific lethal 2 (msl-2), and characterized its product. The encoded protein (MSL-2) consists of 769 amino acid residues and has a RING finger (C3HC4 zinc finger) and a metallothionein-like domain with eight conserved and two non-conserved cysteines. In addition, it contains a positively and a negatively charged amino acid residue cluster and a coiled coil domain that may be involved in protein-protein interactions. Males produce a msl-2 transcript that is shorter than in females, due to differential splicing of an intron of 132 bases in the untranslated leader. Using an antiserum against MSL-2 we have shown that the protein is expressed at a detectable level only in males, where it is physically associated with the X chromosome. Our observations suggest that MSL-2 may be the target of the master regulatory gene Sxl and provide the basic elements of a working hypothesis on the function of MSL-2 in mediating the 2-fold increase in transcription that is characteristic of dosage compensation.
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Affiliation(s)
- S Zhou
- Department of Biology, Emory University, Atlanta, GA 30322, USA
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25
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Abstract
The paraflagellar rod proteins (PAR) purified from Trypanosoma cruzi epimastigotes were shown to protect mice against an otherwise lethal challenge inoculum of 10(3) bloodstream-form trypomastigotes. The injection route used for immunization was shown to have a marked impact on the development of protective immunity. Mice receiving subcutaneous (s.c.) injections of PAR proteins had reduced bloodstream parasitemias and showed 100% survival following challenge. In contrast, mice immunized via the intraperitoneal (i.p.) route developed parasitemia levels equivalent to those of unimmunized controls and did not survive infection. Western blotting (immunoblotting) demonstrated that sera from both i.p. and s.c. immunized mice reacted specifically with PAR proteins; however, the antibody titer of the i.p. immunized mice was approximately 64-fold greater than that of the s.c. immunized mice, suggesting that the protective response in the s.c. immunized mice is cell mediated rather than humoral.
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Affiliation(s)
- R A Wrightsman
- Department of Molecular Biology and Biochemistry, University of California-Irvine 92717
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26
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Wrightsman RA, Dawson BD, Fouts DL, Manning JE. Identification of immunodominant epitopes in Trypanosoma cruzi trypomastigote surface antigen-1 protein that mask protective epitopes. The Journal of Immunology 1994. [DOI: 10.4049/jimmunol.153.7.3148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The gene that encodes trypomastigote surface Ag-1 (TSA-1), a major surface Ag of the bloodstream trypomastigote stage of Trypanosoma cruzi, was expressed in a baculovirus expression system. To determine the epitope(s) in TSA-1 that was recognized during T. cruzi infection and after immunization with TSA-1, subregions of the TSA-1 gene were expressed in a bacterial expression system. As seen by Western blotting, both mice and rabbits immunized with recombinant TSA-1 protein, as well as T. cruzi-infected mice, developed strong immune responses to the carboxyl-proximal region of TSA-1, but show no reaction to the amino-proximal portion of TSA-1. When mice were immunized with either recombinant TSA-1 protein or the carboxyl-proximal region of TSA-1, they did not survive challenge with 10(3) bloodstream trypomastigotes. However, 70% of the mice immunized with the amino-proximal portion of TSA-1 survived challenge with 10(3) bloodstream trypomastigotes. Thus, the immune responses elicited by recombinant TSA-1 or the carboxyl-proximal portion of TSA-1 are nonprotective during T. cruzi infection. In contrast, vaccination with the amino proximal region of TSA-1 elicits a protective immune response. These results suggest that responses to immunodominant epitope(s) within the carboxyl-proximal portion of TSA-1 mask epitopes within the amino-proximal portion that are capable of stimulating host-protective immune responses. It is suggested that immunodominant regions in surface molecules such as TSA-1 may provide a mechanism for the parasite to evade the host immune response by directing the response away from epitopes that have the potential to elicit a reaction that is damaging to the parasite.
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Affiliation(s)
- R A Wrightsman
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
| | - B D Dawson
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
| | - D L Fouts
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
| | - J E Manning
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
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Wrightsman RA, Dawson BD, Fouts DL, Manning JE. Identification of immunodominant epitopes in Trypanosoma cruzi trypomastigote surface antigen-1 protein that mask protective epitopes. J Immunol 1994; 153:3148-54. [PMID: 7522250] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The gene that encodes trypomastigote surface Ag-1 (TSA-1), a major surface Ag of the bloodstream trypomastigote stage of Trypanosoma cruzi, was expressed in a baculovirus expression system. To determine the epitope(s) in TSA-1 that was recognized during T. cruzi infection and after immunization with TSA-1, subregions of the TSA-1 gene were expressed in a bacterial expression system. As seen by Western blotting, both mice and rabbits immunized with recombinant TSA-1 protein, as well as T. cruzi-infected mice, developed strong immune responses to the carboxyl-proximal region of TSA-1, but show no reaction to the amino-proximal portion of TSA-1. When mice were immunized with either recombinant TSA-1 protein or the carboxyl-proximal region of TSA-1, they did not survive challenge with 10(3) bloodstream trypomastigotes. However, 70% of the mice immunized with the amino-proximal portion of TSA-1 survived challenge with 10(3) bloodstream trypomastigotes. Thus, the immune responses elicited by recombinant TSA-1 or the carboxyl-proximal portion of TSA-1 are nonprotective during T. cruzi infection. In contrast, vaccination with the amino proximal region of TSA-1 elicits a protective immune response. These results suggest that responses to immunodominant epitope(s) within the carboxyl-proximal portion of TSA-1 mask epitopes within the amino-proximal portion that are capable of stimulating host-protective immune responses. It is suggested that immunodominant regions in surface molecules such as TSA-1 may provide a mechanism for the parasite to evade the host immune response by directing the response away from epitopes that have the potential to elicit a reaction that is damaging to the parasite.
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Affiliation(s)
- R A Wrightsman
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
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Hilfiker A, Yang Y, Hayes DH, Beard CA, Manning JE, Lucchesi JC. Dosage compensation in Drosophila: the X-chromosomal binding of MSL-1 and MLE is dependent on Sxl activity. EMBO J 1994; 13:3542-50. [PMID: 8062831 PMCID: PMC395258 DOI: 10.1002/j.1460-2075.1994.tb06661.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
In Drosophila, dosage compensation, i.e. the equalization of levels of X-linked gene products in the two sexes, is achieved by the hypertranscription of most X-linked genes in males relative to females. The products of at least four genes, collectively termed male-specific lethal (msl) genes, are required for this process and, at least in the case of three of them, mediate this function through an association with the X chromosome in males. We have studied some of the parameters that affect the association of the msl-1 gene product and found that its presence is dependent on the wild-type function of the other three genes, leading to the conclusion that these gene products contribute to the formation of a multi-subunit complex. Furthermore, the X-chromosomal association of the msl-1 and mle gene products is negatively correlated with the level of function of the master regulatory gene Sxl and can assume either a mosaic or a uniform distribution in the tissues of mutant XX individuals. Surprisingly, we also found that the association of these two msl gene products with the two X chromosomes in females of certain mutant genotypes does not result in the hypertranscription of X-linked genes or in any apparent reduction in viability.
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Affiliation(s)
- A Hilfiker
- Department of Biology, Emory University, Atlanta, GA 30322
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Manning JE, Geyelin AJ, Ansmits LM, Oakey HJ, Knox KW. A comparative study of the aggregation of human, rat and rabbit platelets by members of the Streptococcus sanguis group. J Med Microbiol 1994; 41:10-3. [PMID: 8006939 DOI: 10.1099/00222615-41-1-10] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Aggregation of platelets by bacteria is a potential factor in the pathogenesis of infective endocarditis. Twenty-five strains from the Streptococcus sanguis group, including 15 recent isolates from cases of endocarditis, were compared for their ability to aggregate human and rat platelets over periods of 15 and 25 min, respectively. In each case, 76% of strains caused aggregation; the median time to onset of aggregation was longer for human platelets (12 min) than for rat platelets (1 min). Strains unable to aggregate human platelets included three from cases of endocarditis. There was no correlation between the ability to aggregate human and rat platelets, although the majority of strains (60%) aggregated both. Tests on representative strains for their ability to aggregate rabbit platelets gave results similar to those for rat platelets, including a median time of 1 min to onset of aggregation. The differences in the ability of individual bacterial strains to aggregate human and animal platelets indicate that caution is needed in extrapolating in-vitro observations to the in-vivo situation.
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Affiliation(s)
- J E Manning
- Institute of Dental Research, United Dental Hospital, Sydney, NSW, Australia
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Abstract
The role of gastrin in the control of growth of renal G401 cells isolated from a human nephroblastoma (Wilms' tumour) was investigated. G401 cell growth was enhanced in the presence of exogenous gastrin. Addition of anti-gastrin antibodies to serum-free medium significantly inhibited the growth of G401 cells. G401 cells contained the equivalent of 4.3 pg/10(6) cells of gastrin, and serum-free medium collected over 48 hr from G401 cells contained the equivalent of 38 ng/10(6) cells of gastrin, as determined by radioimmunoassay. Growth of G401 cells was inhibited in a concentration-related way by a variety of gastrin/CCK receptor antagonists. Devazepide and proglumide were, respectively, the most and the least potent inhibitors of G401 cell growth (potency order devazepide > L-365,260 = lorglumide > loxiglumide > benzotript > proglumide). These gastrin/CCK receptor antagonists had similar growth-inhibitory activities in human colonic adenocarcinoma HCT-116 cells. Growth of HCT-116 cells was stimulated to a lesser extent, as compared with G401 cells, by exogenous gastrin, and endogenous gastrin was not detectable in HCT-116 cells. The results are consistent with a role for a gastrin-like peptide in the control of growth of a renal cell line. The data suggest that gastrin/CCK receptor antagonists warrant further investigation as therapeutic agents for the control of gastrin-responsive tumours derived from outside, as well as inside, the gastrointestinal tract, including tumours derived from the kidney.
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Affiliation(s)
- M Blackmore
- Department of Physiological Sciences, University of Newcastle upon Tyne, Medical School, UK
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Abstract
Platelet aggregation is believed to be a virulence factor in infective endocarditis. Other factors may be adhesion to components of thrombotic vegetations, particularly platelets, fibronectin and fibrinogen. Two strains from the Streptococcus sanguis group (SSG) were chosen for comparative study on the basis that one aggregated both human and rat platelets and the other lacked this capacity. Both strains caused endocarditis in the rat model but the aggregating strain was found in higher numbers in the excised vegetations. The nonaggregating strain was unable to bind to human or rat platelets but could bind insoluble fibronectin, insoluble fibrinogen and platelet-fibrin clots from both sources, albeit to a lesser extent than the aggregating strain. These results suggest that whereas adhesion to, and aggregation of, platelets are not essential events in the initiation of the pathogenesis of experimental endocarditis, they may be factors contributing to virulence.
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Affiliation(s)
- J E Manning
- Institute of Dental Research, United Dental Hospital, Sydney NSW, Australia
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Manning JE, Bixler PA. The magic of a million: who says employees can't raise a million? Fund Raising Manage 1994; 24:21-5. [PMID: 10131674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Ruef BJ, Dawson BD, Tewari D, Fouts DL, Manning JE. Expression and evolution of members of the Trypanosoma cruzi trypomastigote surface antigen multigene family. Mol Biochem Parasitol 1994; 63:109-20. [PMID: 8183309 DOI: 10.1016/0166-6851(94)90013-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The trypomastigote specific surface antigens of Trypanosoma cruzi are encoded by a supergene family which includes the TSA family. The TSA family is characterized by the presence of a 27-bp tandem repeat array in the coding region. Here, we report the characterization and analysis of the three TSA family members in the Esmeraldo strain of the parasite. In this strain 2 distinct telomeric members are expressed abundantly as 3.7-kb mRNAs, while the remaining member is located at an internal chromosomal site and is expressed at less than 2% of the level seen for the telomeric members. Based on hybridization to DNA separated by PFGE, 3 chromosomes of sizes 1.8 Mb, 0.98 Mb, and 0.90 Mb each contain one of the telomeric members. In addition, the two smaller chromosomes also contain the single internal member. Since both chromosomes contain similar TSA family members, and vary only slightly in size, we suggest that they are homologues. Comparisons of the nucleotide sequences of the different members of the family show that the internal gene differs from the telomeric genes primarily in sequences found 3' of the repeat array. These comparisons also reveal that the three genes are analogous, supporting the hypothesis that short segments between the family members are exchanged by gene conversion events. We propose that similar conversion events between members of different gene families may generate some of the diversity found within the supergene family.
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Affiliation(s)
- B J Ruef
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
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Affiliation(s)
- B J Ruef
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
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Palmer MJ, Mergner VA, Richman R, Manning JE, Kuroda MI, Lucchesi JC. The male-specific lethal-one (msl-1) gene of Drosophila melanogaster encodes a novel protein that associates with the X chromosome in males. Genetics 1993; 134:545-57. [PMID: 8325488 PMCID: PMC1205497 DOI: 10.1093/genetics/134.2.545] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Male-specific lethal-one (msl-1) is one of four genes that are required for dosage compensation in Drosophila males. To determine the molecular basis of msl-1 regulation of dosage compensation, we have cloned the gene and characterized its products. The predicted msl-1 protein (MSL-1) has no significant similarity to proteins in the current data bases but contains an acidic N terminus characteristic of proteins involved in transcription and chromatin modeling. We present evidence that the msl-1 protein is associated with hundreds of sites along the length of the X chromosome in male, but not in female, nuclei. Our findings support the hypothesis that msl-1 plays a direct role in increasing the level of X-linked gene transcription in male nuclei.
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Affiliation(s)
- M J Palmer
- Department of Biology, University of North Carolina, Chapel Hill 27599-3280
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Abstract
STUDY OBJECTIVE To determine if delivery of epinephrine to the peripheral arterial system by an aortic arch catheter is more effective than central venous epinephrine administration during cardiac resuscitation. DESIGN Randomized, nonblinded, controlled trial. TYPE OF PARTICIPANTS Sixteen mongrel canines (25 to 31 kg). INTERVENTIONS Animals had aortic arch pressure, and right atrial pressure, superior vena cava infusion, and descending aortic arch infusion catheters placed using fluoroscopy. After ten minutes of ventricular fibrillation, three DC countershocks were delivered over one minute. If unsuccessful, CPR at 120 compressions per minute was begun, and at 60 seconds of CPR, epinephrine (1 mg/50 mL normal saline) was administered either through the superior vena cava or the aortic arch catheter followed by one more minute of CPR. Defibrillation then was attempted and, if unsuccessful, further resuscitative efforts followed advanced cardiac life support guidelines, except route and dose of epinephrine remained the same. MEASUREMENTS AND MAIN RESULTS Aortic arch pressure, right atrial pressure, and coronary perfusion pressure (diastolic aortic arch pressure minus diastolic right atrial pressure) were recorded continuously. Aortic arch pressure and coronary perfusion pressure increased more rapidly and to a greater magnitude with aortic arch-epinephrine than superior vena cava-epinephrine. Coronary perfusion pressure doubled by ten seconds in seven of eight in the aortic arch-epinephrine group versus none in the superior vena cava-epinephrine group. Aortic arch pressure and coronary perfusion pressure increases consistently plateaued within 60 seconds after aortic arch-epinephrine but not after superior vena cava-epinephrine. Return of spontaneous circulation was faster (P < .05) in the aortic arch-epinephrine group. Maximal coronary perfusion pressure after epinephrine correlated with the coronary perfusion pressure immediately before epinephrine administration in both groups, but more strongly in the aortic arch-epinephrine group (P = .0001). CONCLUSION For an equivalent dose of epinephrine, aortic arch administration produces a more rapid response and more rapid peak effect than central venous administration. The combination of aortic arch-epinephrine administration and aortic pressure monitoring may be useful when initial standard resuscitative measures have not been successful.
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Affiliation(s)
- J E Manning
- Department of Emergency Medicine, Chapel Hill School of Medicine, University of North Carolina
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Huang AJ, Manning JE, Bandak TM, Ratau MC, Hanser KR, Silverstein SC. Endothelial cell cytosolic free calcium regulates neutrophil migration across monolayers of endothelial cells. J Cell Biol 1993; 120:1371-80. [PMID: 8449983 PMCID: PMC2119745 DOI: 10.1083/jcb.120.6.1371] [Citation(s) in RCA: 257] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Polymorphonuclear leukocytes (PMN) traverse an endothelial cell (EC) barrier by crawling between neighboring EC. Whether EC regulate the integrity of their intercellular adhesive and junctional contacts in response to chemotaxing PMN is unresolved. EC respond to the binding of soluble mediators such as histamine by increasing their cytosolic free calcium concentration ([Ca++]i) (Rotrosen, D., and J.I. Gallin. 1986. J. Cell Biol. 103:2379-2387) and undergoing shape changes (Majno, G., S. M. Shea, and M. Leventhal. 1969. J. Cell Biol. 42:617-672). Substances such as leukotriene C4 (LTC4) and thrombin, which increased the permeability of EC monolayers to ions, as measured by the electrical resistance of the monolayers, transiently increased EC [Ca++]i. To determine whether chemotaxing PMN cause similar changes in EC [Ca++]i, human umbilical vein endothelial cells (HUVEC) maintained as monolayers were loaded with fura-2. [Ca++]i was measured in single EC during PMN adhesion to and migration across these monolayers. PMN-EC adhesion and transendothelial PMN migration in response to formyl-methionyl-leucyl-phenylalanine (fMLP) as well as to interleukin 1 (IL-1) treated EC induced a transient increase in EC [Ca++]i which temporally corresponded with the time course of PMN-EC interactions. When EC [Ca++]i was clamped at resting levels with a cell permeant calcium buffer, PMN migration across EC monolayers and PMN induced changes in EC monolayer permeability were inhibited. However, clamping of EC [Ca++]i did not inhibit PMN-EC adhesion. These studies provide evidence that EC respond to stimulated PMN by increasing their [Ca++]i and that this increase in [Ca++]i causes an increase in EC monolayer permeability. Such [Ca++]i increases are required for PMN transit across an EC barrier. We suggest EC [Ca++]i regulates transendothelial migration of PMN by participating in a signal cascade which stimulates EC to open their intercellular junctions to allow transendothelial passage of leukocytes.
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Affiliation(s)
- A J Huang
- Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York 10032
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Beard CA, Saborio JL, Tewari D, Krieglstein KG, Henschen AH, Manning JE. Evidence for two distinct major protein components, PAR 1 and PAR 2, in the paraflagellar rod of Trypanosoma cruzi. Complete nucleotide sequence of PAR. J Biol Chem 1992; 267:21656-62. [PMID: 1400477] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The previously identified major protein components of the paraflagellar rod in Trypanosoma cruzi, PAR 1 and PAR 2, were analyzed to determine if they are distinct proteins or different conformations of a single polypeptide as has been suggested for other trypanosomatids. Amino acid sequence analysis showed PAR 1 and PAR 2 to be two distinct polypeptides. Antibodies specific against either PAR 1 or PAR 2 were shown to each react with a distinct band in Western blots of paraflagellar isolates of T. cruzi and other trypanosomatids if rigorous protease inhibition was used. The PAR 2 message was isolated and characterized by Northern blot and nucleic acid sequence analysis. Preliminary analysis of the PAR 2 gene indicates that PAR 2 is a member of a multigene family with all members residing on a single chromosome.
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Affiliation(s)
- C A Beard
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
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Manning JE, Murphy CA, Hertz CM, Perretta SG, Mueller RA, Norfleet EA. Selective aortic arch perfusion during cardiac arrest: a new resuscitation technique. Ann Emerg Med 1992; 21:1058-65. [PMID: 1514716 DOI: 10.1016/s0196-0644(05)80645-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
STUDY OBJECTIVES To demonstrate the technique of selective aortic arch perfusion during cardiac arrest and to observe the hemodynamic effects of volume infusion and aortic epinephrine administration. DESIGN Sequential series, nonrandomized, noncontrolled. TYPE OF PARTICIPANTS Fourteen mongrel dogs weighing 21 to 36 kg. INTERVENTIONS Animals had midaortic arch pressure, right atrial pressure, and descending aortic arch balloon occlusion catheters placed. After ten minutes of ventricular fibrillation, balloon inflation and aortic arch infusions were initiated as follows: group 1 (six), 30 mL/kg/min of 0.9% NaCl for two minutes; group 2 (four), 30 mL/kg/min of oxygenated lactated Ringer's with 2 mg/L epinephrine for two minutes, followed by CPR; and group 3 (four), 20 mL/kg/min of oxygenated perfluorochemicals with 4 mg/L epinephrine for one minute, then CPR. MEASUREMENTS AND MAIN RESULTS Midaortic arch pressure, right atrial pressure, and coronary perfusion pressure each rose significantly in all groups. Midaortic arch pressure and coronary perfusion pressure increases were greater in groups 2 and 3 than in group 1. In groups 1 and 2, right atrial pressure increases at end-selective aortic arch perfusion were excessive as midaortic arch pressure and right atrial pressure increased linearly and similarly after 20 to 30 seconds. In groups 2 and 3, CPR-diastolic midaortic arch pressure and coronary perfusion pressure after selective aortic arch perfusion were good and similar to midaortic arch pressure and coronary perfusion pressure at end-selective aortic arch perfusion. CONCLUSION Selective aortic arch perfusion is technically feasible, but excessive right atrial pressure increases limit maximal infusion rates and volumes. Selective aortic arch perfusion infusates with epinephrine produce greater midaortic arch pressure and coronary perfusion pressure during infusion than infusate without epinephrine. Controlled studies are needed to determine if selective aortic arch perfusion improves resuscitation outcome.
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Affiliation(s)
- J E Manning
- Department of Emergency Medicine, University of North Carolina, Chapel Hill, School of Medicine
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Ghosh S, Lucchesi JC, Manning JE. The non-dosage compensated LSP1-alpha gene of Drosophila melanogaster lies immediately downstream of the dosage compensated L12 gene. Mol Gen Genet 1992; 233:49-52. [PMID: 1376406 DOI: 10.1007/bf00587560] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The X-linked gene LSP1-alpha of Drosophila melanogaster, expressed in the third larval instar, does not exhibit dosage compensation at its normal locus but does compensate when it is relocated to ectopic sites on the X chromosome. A transcription unit designated L12, which is active in the second larval instar and capable of encoding a putative protein of 28.5 kDa, lies immediately downstream from LSP1-alpha. We have determined that L12 is dosage compensated by measuring the steady-state level of its transcript in male and female larvae. The difference in response of these two adjacent genes should be taken into consideration when models of the mechanism of dosage compensation are formulated.
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Affiliation(s)
- S Ghosh
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
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42
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Fouts DL, Ruef BJ, Ridley PT, Wrightsman RA, Peterson DS, Manning JE. Nucleotide sequence and transcription of a trypomastigote surface antigen gene of Trypanosoma cruzi. Mol Biochem Parasitol 1991; 46:189-200. [PMID: 1717846 DOI: 10.1016/0166-6851(91)90043-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In previous studies we identified a 500-bp segment of the gene, TSA-1, which encodes an 85-kDa trypomastigote-specific surface antigen of the Peru strain of Trypanosoma cruzi. TSA-1 was shown to be located at a telomeric site and to contain a 27-bp tandem repeat unit within the coding region. This repeat unit defines a discrete subset of a multigene family and places the TSA-1 gene within this subset. In this study, we present the complete nucleotide sequence of the TSA-1 gene from the Peru strain. By homology matrix analysis, fragments of two other trypomastigote specific surface antigen genes, pTt34 and SA85-1.1, are shown to have extensive sequence homology with TSA-1 indicating that these genes are members of the same gene family as TSA-1. The TSA-1 subfamily was also found to be active in two other strains of T. cruzi, one of which contains multiple telomeric members and one of which contains a single non-telomeric member, suggesting that transcription is not necessarily dependent on the gene being located at a telomeric site. Also, while some of the sequences found in this gene family are present in 2 size classes of poly(A)+ RNA, others appear to be restricted to only 1 of the 2 RNA classes.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Antigens, Surface/genetics
- Antigens, Surface/immunology
- Base Sequence
- Blotting, Northern
- Blotting, Southern
- Endodeoxyribonucleases/metabolism
- Gene Expression
- Molecular Sequence Data
- Multigene Family
- Nucleic Acid Hybridization
- Poly A/genetics
- RNA/genetics
- RNA, Messenger
- RNA, Protozoan/genetics
- Sequence Homology, Nucleic Acid
- Transcription, Genetic
- Trypanosoma cruzi/genetics
- Trypanosoma cruzi/immunology
- Trypanosoma cruzi/metabolism
- Variant Surface Glycoproteins, Trypanosoma
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Affiliation(s)
- D L Fouts
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
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Ruef BJ, Hecht JH, Manning JE. A method of identifying and isolating a unique member of a multigene family: application to a trypanosome surface antigen gene. Nucleic Acids Res 1991; 19:1811-5. [PMID: 2030963 PMCID: PMC328109 DOI: 10.1093/nar/19.8.1811] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A chimeric oligonucleotide was constructed using DNA sequences from two distal regions of a cDNA which encodes a major surface antigen (TSA-1) of Trypanosoma cruzi. Conditions were found that allowed the chimeric oligonucleotide to hybridize only to a 5.4 kb EcoRI fragment in a Southern blot of total genomic DNA. The 5.4 kb EcoRI genomic DNA fragment has previously been shown to be located at a telomeric site, thus the studies described here directly demonstrate that the TSA-1 gene is telomeric in location. It is also shown that the chimeric oligonucleotide can be used to selectively identify recombinant lambda phage which harbor the TSA-1 gene using standard library screening procedures. Since these studies demonstrate that a chimeric oligonucleotide can be used to identify in both Southern blots and library screens a single member among the more than sixty members of the TSA-1 gene family, it seems likely that chimeric oligonucleotides may be of general use in studies involving repetitive DNA sequence families.
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Affiliation(s)
- B J Ruef
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
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Saborio JL, Wrightsman RA, Kazuko SG, Granger BS, Manning JE. Trypanosoma cruzi: identification of a surface antigen restricted to the flagellar region of the infective form of the parasite. Exp Parasitol 1990; 70:411-8. [PMID: 2182336 DOI: 10.1016/0014-4894(90)90125-v] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A hybridoma cell line was derived from spleen cells of B6D2 mice infected with the Peru strain of Trypanosoma cruzi. The monoclonal antibody produced by this hybridoma, designated mAb20H1, reacts exclusively with molecular components of trypomastigotes, the infective form of the parasite. The results of indirect immunofluorescence and of immunoelectron microscopy with gold-tagged antibodies indicate that the 20H1 antigen is restricted to the surface of the part of the flagellum in contact with the cell body and to the surface of the cell body in the immediate vicinity of this organelle. Western blot analysis showed that the 20H1 antigen consists of four to five different molecules with sizes between 34 and 41 kDa, and that these molecules are glycoproteins with affinity for concanavalin A. In other strains of T. cruzi, mAb20H1 reacts with glycoproteins with apparent sizes that range between 37 and 43 kDa in the CL, Esmeraldo and Y strains, and between 41 and 45 kDa in the Silvio strain.
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Affiliation(s)
- J L Saborio
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
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Abstract
In previous studies we identified a 500 bp DNA fragment from the genome of Trypanosoma cruzi which encoded epitopes present in an 85 kd trypomastigote-specific surface antigen. A unique feature of this DNA insert was the presence of a 27 bp tandem repeat unit within the putative coding region. The findings presented here show that the gene which encodes this particular surface protein is a member of a multigene family, and that the 27 bp repeat unit defines a subset of this family. Only four separate members of the family contain sequences homologous to the 27 bp repeat unit. Of these, three have been cloned and shown by direct nucleotide sequence analysis not to contain the original 500 bp fragment. By restriction enzyme analysis, the 500 bp fragment is inferred to be present in a 5.4 kb EcoRI genomic DNA fragment that is refractory to isolation by standard cloning procedures. Preferential sensitivity of this fragment to digestion with Bal31 nuclease indicates that it is likely to be telomeric, thus explaining the inability to obtain it in several different recombinant DNA libraries. In order to determine which of the four members were transcribed, 26 cDNA recombinants having sequence homology with the 27 bp repeat were examined. Restriction enzyme maps and nucleotide sequence analysis of these cDNAs indicate that transcription occurs almost exclusively from the telomeric member of the family.
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Affiliation(s)
- D S Peterson
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
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Manning JE, Pelikan PCD, Niemann JT. Left ventricular volume and aortic flow relationships during high-impulse CPR: Implications regarding mechanism of blood flow. Ann Emerg Med 1989. [DOI: 10.1016/s0196-0644(89)80706-1] [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: 12/01/2022]
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Abstract
An enzyme linked immune sorbent assay (ELISA) was developed to measure bacterial surface lipoteichoic acid (LTA). Numerous strains of oral streptococci belonging to the 'viridans' group were examined on three separate occasions. The results show that, under these cultural conditions, oral streptococci do not normally express LTA on the cell surface. Occasionally strains produced amounts of LTA detectable using the ELISA but this was not a reproducible phenomenon.
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Affiliation(s)
- S D Hogg
- Department of Oral Biology, The University, Newcastle upon Tyne, U.K
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Ghosh S, Chatterjee RN, Bunick D, Manning JE, Lucchesi JC. The LSP1-alpha gene of Drosophila melanogaster exhibits dosage compensation when it is relocated to a different site on the X chromosome. EMBO J 1989; 8:1191-6. [PMID: 2501087 PMCID: PMC400933 DOI: 10.1002/j.1460-2075.1989.tb03491.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The LSP1-alpha gene of Drosophila melanogaster is located on the X chromosome at 11B yet is not dosage compensated. In order to determine if this gene is inherently incapable of dosage compensation or if it does not compensate because the appropriate regulatory cis-acting sequences are absent from its chromosomal domain, we have undertaken to relocate it to ectopic sites on the X chromosome. To differentiate between the transcripts produced by the transduced gene and those produced by the indigenous gene, we inserted a 500-bp sequence of mouse DNA into the LSP1-alpha clone prior to using it for transformation. Our results show that the LSP1-alpha gene exhibits equivalent levels of transcripts in the two sexes when it is relocated to either an autosomal site or to an ectopic site on the X chromosome. We conclude that the LSP1-alpha gene is capable of dosage compensation.
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Affiliation(s)
- S Ghosh
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
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Gutierrez AG, Christensen AC, Manning JE, Lucchesi JC. Cloning and dosage compensation of the 6-phosphogluconate dehydrogenase gene (Pgd+) of Drosophila melanogaster. Dev Genet 1989; 10:155-61. [PMID: 2500280 DOI: 10.1002/dvg.1020100305] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Using a heterologous rat cDNA probe, we have identified a 14.7 kbp Drosophila melanogaster genomic clone containing the X-linked gene Pgd+, which encodes the enzyme 6-phosphogluconate dehydrogenase (6PGD). We used in situ hybridization to larval polytene chromosomes, a somatic transient expression assay for enzyme activity, and the rescue of the lethal Pgd- phenotype by germline transformation to verify the identity of the gene. A 7.4 kbp fragment including the gene and approximately 1.2 kbp of upstream and 1.8 kbp of downstream sequences was relocated to autosomal ectopic sites by germline transformation; this transduced gene exhibits levels of enhanced activity in males comparable to those of the indigenous gene at its normal X chromosome locus. We conclude that the sequences responsible for dosage compensation of Pgd+ are included in this fragment.
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Affiliation(s)
- A G Gutierrez
- Department of Biology, University of North Carolina, Chapel Hill 27514
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Abstract
Fibronectin-coated hydroxyapatite (FnHA) beads were used in a model adhesion assay to isolate the lipoteichoic acid (LTA) mediated adhesion of oral streptococci. Representative strains of the commonly isolated viridans streptococci were incubated with FnHA beads in the presence and absence of exogenous LTA. The LTA inhibited the adhesion of all strains to a greater or lesser extent, but only a very few strains were inhibited by more than 90%. Strains of Streptococcus sanguis Type II and Streptococcus mitis which synthesize an amphiphile other than LTA were also inhibited. The findings provided circumstantial evidence for the involvement of LTA in the adhesion of this group of oral bacteria.
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Affiliation(s)
- S D Hogg
- Department of Oral Biology, The University, Newcastle upon Tyne, UK
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