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Taira DA, Safran DG, Seto TB, Rogers WH, Inui TS, Montgomery J, Tarlov AR. Do patient assessments of primary care differ by patient ethnicity? Health Serv Res 2001; 36:1059-71. [PMID: 11775667 PMCID: PMC1089278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
OBJECTIVE To determine if patient assessments (reports and ratings) of primary care differ by patient ethnicity. DATA SOURCES/STUDY DESIGN A self-administered patient survey of 6,092 Massachusetts employees measured seven defining characteristics of primary care: (1) access (financial, organizational); (2) continuity (longitudinal, visit based); (3) comprehensiveness (knowledge of patient, preventive counseling); (4) integration; (5) clinical interaction (communication, thoroughness of physical examinations); (6) interpersonal treatment; and (7) trust. The study employed a cross-sectional observational design. PRINCIPAL FINDINGS Asians had the lowest primary care performance assessments of any ethnic group after adjustment for socioeconomic and other factors. For example, compared to whites, Asians had lower scores for communication (69 vs. 79, p = .001) and comprehensive knowledge of patient (56 vs. 48, p = .002), African Americans and Latinos had less access to care, and African Americans had less longitudinal continuity than whites. CONCLUSIONS We do not know what accounts for the observed differences in patient assessments of primary care. The fact that patient reports as well as the more subjective ratings of care differed by ethnicity suggests that quality differences might exist that need to be addressed.
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Tee W, Montgomery J, Dyall-Smith M. Bacteremia caused by a Helicobacter pullorum-like organism. Clin Infect Dis 2001; 33:1789-91. [PMID: 11595983 DOI: 10.1086/323983] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2001] [Revised: 07/02/2001] [Indexed: 11/03/2022] Open
Abstract
We report a case of bacteremia caused by a Helicobacter pullorum-like organism in a 35-year-old man with pyrexia of unknown origin. Culture of blood samples obtained at admission yielded a motile, spiral-shaped gram-negative rod, and 16S rRNA gene sequencing identified this organism as Helicobacter pullorum-like, showing 23 base differences compared with the recently described "Helicobacter canadensis" (a recently proposed group that had previously been classified within H. pullorum). We believe that this is the first report of bacteremia caused by this organism.
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Ste-Marie L, Hazell AS, Bémeur C, Butterworth R, Montgomery J. Immunohistochemical detection of inducible nitric oxide synthase, nitrotyrosine and manganese superoxide dismutase following hyperglycemic focal cerebral ischemia. Brain Res 2001; 918:10-9. [PMID: 11684037 DOI: 10.1016/s0006-8993(01)02903-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We have characterized the temporal changes in iNOS, MnSOD and nitrotyrosine immune reactivity in a rat model of permanent middle cerebral artery occlusion under acute hyperglycemic or normoglycemic conditions followed by either 3- or 24-h recovery. We found that the macroscopic labeling pattern for all three antibodies colocalized with the ischemic core and penumbra which was determined by cresyl violet histological evaluation in adjacent sections. Hyperglycemia induced prior to ischemia resulted in earlier infarction which correlated with increased immunoreactivity for iNOS, MnSOD and nitrotyrosine. In the penumbral region of the frontal cortex, labeling of specific cell structures was largely limited to cortical neurons near the corpus callosum and was apparent earlier in the hyperglycemic rats. Increased polymorphonuclear leukocyte adhesion in blood vessels was observed at 24 h in the hyperglycemic group. At both of the recovery times studied, we observed only minor vascular staining for nitrotyrosine and none for iNOS. Our results are consistent with hyperglycemia resulting in an early and concomitant increase in both superoxide and nitric oxide production which can lead to peroxynitrite formation that then nitrates tyrosine residues. It would appear that hyperglycemic ischemia contributes to the early induction of key enzymes involved in nitric oxide bioavailability.
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Abstract
BACKGROUND Transfusion-related acute lung injury (TRALI) is a rare condition that is commonly associated with the transfusion of donor plasma containing WBC antibodies. Biologically active lipids that accumulate during storage of RBCs and platelets may also cause TRALI. There has been only one previously reported case of recurrent TRALI. CASE REPORT A patient received a transfusion 2 days after undergoing hysterectomy; she developed TRALI after receiving the transfusion. The patient recovered after being on ventilation for 6 days but received an additional transfusion and had a second episode of TRALI, which required further ventilation. RESULTS Laboratory investigation of the first episode of TRALI suggested the presence of HLA-A2 (N = 1) and granulocyte-specific IgM antibodies (N = 2) in the sera from three of the donors. All three sera reacted in crossmatch studies with the patient's granulocytes and lymphocytes. Lymphocyte-specific IgG antibodies were detected in the patient's serum. There was no evidence to suggest the involvement of WBC antibodies in the second episode of TRALI. Antibody screening of the donors' samples and both forward and reverse crossmatch studies were negative. CONCLUSION The first episode of TRALI seems to be due to the action of HLA-A2 and granulocyte-specific IgM antibodies. The second episode may have been due to the action of lipid neutrophil-priming agents in the donors' units in association with the patient's underlying pulmonary condition (i.e., recovering from lung injury). TRALI can recur if a patient requires further transfusion support shortly after an initial episode of TRALI.
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Schroeder RE, Morrison EE, Cavanaugh C, West MP, Montgomery J. Improving communication among health professionals through education: a pilot study. THE JOURNAL OF HEALTH ADMINISTRATION EDUCATION 2001; 17:175-98. [PMID: 11184900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Communication can be thought of as a message that is sent, received, and understood. Each discipline of the health profession has its own jargon and means of expressing ideas in shorthand. These separate forms of communicating are effective among those of the same background but are often at the root of misunderstandings between professional groups. This article reviews communication theory and traces the difficulties created when inter-disciplinary teams of healthcare try to work together and communicate. As multi-disciplinary teams are increasingly dealing with the complex problems of today's healthcare system, clear communication and understanding has never been more important. If educators could assist in creating an understanding of vocabulary used for decision processes, communication could improve. The authors of this study performed a multi-stage Delphi survey that grouped terms used by administrators and clinicians and produced a lexicon of corresponding terms. An expert panel then reviewed and modified the list. The result is a lexicon that can be useful to assist clinicians and administrators to communicate with each other. By utilizing clinical terminology, or vice versa, instead of management or clinical jargon, some of the translation done by administration or clinicians could be reduced. Examples of how the lexicon can be utilized are provided in the article. This includes using it in health administration education to demonstrate the variances in clinical/managerial terms. It could also be provided as a primer to physicians, nurses, and other health professionals who assume administrative positions to enhance their communication with administrators.
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83
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Jensen AT, Curtis J, Montgomery J, Handman E, Theander TG. Molecular and immunological characterisation of the glucose regulated protein 78 of Leishmania donovani(1). BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1549:73-87. [PMID: 11566370 DOI: 10.1016/s0167-4838(01)00240-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
To identify novel potential Leishmania vaccine antigens, antibodies from patients with visceral leishmaniasis (VL) were used to isolate clones from a cDNA expression library of L. donovani amastigotes. Glucose Regulated Protein (GRP78), a member of the 70 kDa heat-shock protein family was identified and characterised. The GRP78 gene was localised to chromosome 15 in L. donovani, L. major, and L. mexicana by pulse-field gel electrophoresis. The Leishmania GRP78 protein contain a carboxy-terminal endoplasmic reticulum retention signal sequence (MDDL) as does the Trypanosoma cruzi GRP78. Immunofluorescence using antibodies to the recombinant DNA-derived GRP78 protein showed staining localised to reticular material throughout the cytoplasm and in the perinuclear region of promastigotes, suggesting that the protein is localised in the endoplasmic reticulum. The protective efficacy of GRP78 was assessed in mice vaccine experiments. A GRP78 DNA vaccine primed for an immune response that protected C57Bl/6 and C3H/He mice against infection with L. major. Similarly vaccination with a recombinant form of GRP78 purified from Escherichia coli and administered with Freund's as adjuvant induced protective immunity in C57Bl/6 mice.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, Protozoan/immunology
- Base Sequence
- Blotting, Northern
- Cloning, Molecular
- Disease Models, Animal
- Electrophoresis, Gel, Pulsed-Field
- Endoplasmic Reticulum Chaperone BiP
- Gene Library
- Genes, Protozoan
- HSP70 Heat-Shock Proteins
- Heat-Shock Proteins/genetics
- Heat-Shock Proteins/immunology
- Heat-Shock Proteins/metabolism
- Humans
- Leishmania donovani/genetics
- Leishmania donovani/immunology
- Leishmania donovani/metabolism
- Leishmaniasis/immunology
- Mice
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Microscopy, Confocal
- Molecular Sequence Data
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Protozoan Proteins/metabolism
- Protozoan Vaccines/administration & dosage
- Protozoan Vaccines/immunology
- Vaccination
- Vaccines, DNA/administration & dosage
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Franck LS, Hummel D, Connell K, Quinn D, Montgomery J. The safety and efficacy of peripheral intravenous catheters in ill neonates. Neonatal Netw 2001; 20:33-8. [PMID: 12144220 DOI: 10.1891/0730-0832.20.5.33] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
This article describes the use of a quality improvement clinical audit approach to identify insertion practices, duration of therapy, and complications related to peripheral intravenous catheters. These data provide evidence for adherence to practice standards and benchmarks for evaluation of new interventions to improve the safety and efficacy of intravenous access practices. Implications for quality improvement and clinical research related to intravenous-device practices within the neonatal intensive care unit are discussed.
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85
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Bud P, Montgomery J, Evans J, Barreiro B. Human tooth enamel as a record of the comparative lead exposure of prehistoric and modern people. THE SCIENCE OF THE TOTAL ENVIRONMENT 2000; 263:1-10. [PMID: 11194143 DOI: 10.1016/s0048-9697(00)00604-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
There is a considerable body of evidence to support the contention that the atmospheric Pb burden is now considerably greater than it was in the remote past. However, as there are a diversity of potential environmental pathways leading to Pb ingestion, it is not clear how atmospheric Pb levels relate to human exposure. It is necessary to establish a baseline for human exposure to Pb from natural sources in the pre-metallurgical past, with which contemporary exposure can be compared. This paper addresses this issue by comparing the Pb content of human dental enamel--an established proxy for Pb exposure--from modern and archaeological, pre-metallurgical individuals using thermal and plasma ionisation mass spectrometry. It is shown that mean Neolithic enamel Pb contents are approximately 0.31 +/- 0.04 ppm. These values are only one order of magnitude lower than previously reported data for the same tissues for modern juveniles, despite an established 400-fold increase in the atmospheric Pb burden. The results suggest that 'natural' exposure to Pb in food and water may have been higher than previously thought, and that the link between atmospheric Pb and human exposure warrants further investigation.
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86
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Tee W, Hinds S, Montgomery J, Dyall-Smith ML. A probable new Helicobacter species isolated from a patient with bacteremia. J Clin Microbiol 2000; 38:3846-8. [PMID: 11015417 PMCID: PMC87490 DOI: 10.1128/jcm.38.10.3846-3848.2000] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A probable new Helicobacter species was isolated from the blood of a 14-month-old aboriginal child who presented with vomiting, diarrhea, fever, and dry cough. The most similar 16S rRNA gene sequence was that of Helicobacter fennelliae CCUG 18820(T) but the new sequence differed from it by at least 32 base substitutions and by the presence of a large (353-nucleotide) intervening sequence.
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87
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Montgomery J, Carton G, Voigt R, Baker C, Diebel C. Sensory processing of water currents by fishes. Philos Trans R Soc Lond B Biol Sci 2000; 355:1325-7. [PMID: 11079424 PMCID: PMC1692841 DOI: 10.1098/rstb.2000.0693] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Water currents are extremely important in the aquatic environment and play a very significant role in the lives of fishes. Sensory processing of water currents involves a number of sensory modalities including the inner ear, vision, tactile sense and the mechanosensory lateral line. The inner ear will detect whole-body accelerations generated by changes in flow, or by turbulence, whereas visual and tactile inputs will signal translational movement with respect to an external visual or tactile reference frame. The superficial neuromasts of the mechanosensory lateral line detect flow over the surface of the body and have the appropriate anatomical distribution and physiological properties to signal the strength and the direction of flow and, hence, contribute to the detection of regional differences in flow over different parts of the body.
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88
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Montgomery J. Nickel-catalyzed cyclizations, couplings, and cycloadditions involving three reactive components. Acc Chem Res 2000; 33:467-73. [PMID: 10913235 DOI: 10.1021/ar990095d] [Citation(s) in RCA: 268] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Transition-metal-catalyzed processes that allow the efficient coupling of three reactive components in a chemoselective and stereoselective fashion are particularly useful in the synthesis of complex organic molecules from simple, readily available substrates. This account outlines work primarily from the author's laboratory on the development of nickel-catalyzed multicomponent coupling processes. An overview of new synthetic methods, a discussion of potential mechanisms, and a description of applications in complex-molecule synthesis are provided.
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89
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Pavlidis P, Montgomery J, Madison DV. Presynaptic protein kinase activity supports long-term potentiation at synapses between individual hippocampal neurons. J Neurosci 2000; 20:4497-505. [PMID: 10844019 PMCID: PMC6772468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
Simultaneous microelectrode recording from two individual synaptically connected neurons enables the direct analysis of synaptic transmission and plasticity at a minimal synaptic connection. We have recorded from pairs of CA3 pyramidal neurons in organotypic hippocampal slices to examine the properties of long-term potentiation (LTP) at such minimal connections. LTP in minimal connections was found to be identical to the NMDA-dependent LTP expressed by CA3-CA1 synapses, demonstrating this system provides a good model for the study of the mechanisms of LTP expression. The LTP at minimal synaptic connections does not behave as a simple increase in transmitter release probability, because the amplitude of unitary EPSCs can increase several-fold, unlike what is observed when release probability is increased by raising extracellular calcium. Taking advantage of the relatively short axon connecting neighboring CA3 neurons, we found it feasible to introduce pharmacological agents to the interior of presynaptic terminals by injection into the presynaptic soma and have used this technique to investigate presynaptic effects on basal transmission and LTP. Presynaptic injection of nicotinamide reduced basal transmission, but LTP in these pairs was essentially normal. In contrast, presynaptic injection of H-7 significantly depressed LTP but not basal transmission, indicating a specific role of presynaptic protein kinases in LTP. These results demonstrate that pharmacological agents can be directly introduced into the presynaptic cell and that a purely presynaptic perturbation can alter this plasticity.
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90
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Montgomery J, Pearson K, Thomas W, Rhoades E, Lorenz D. Folic acid knowledge and multivitamin use among Oklahoma women. THE JOURNAL OF THE OKLAHOMA STATE MEDICAL ASSOCIATION 2000; 93:256. [PMID: 10860295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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91
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Ste-Marie L, Vachon P, Vachon L, Bémeur C, Guertin MC, Montgomery J. Hydroxyl radical production in the cortex and striatum in a rat model of focal cerebral ischemia. Can J Neurol Sci 2000; 27:152-9. [PMID: 10830350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
BACKGROUND Increases in hydroxyl radical production have been used as evidence of oxidative stress in cerebral ischemia/ reperfusion. Ischemia can also induce increased dopamine release from the striatum that may contribute to hydroxyl radical formation. We have compared hydroxyl radical production in the cortex and striatum as an index of oxidative stress in a rat model of focal cerebral ischemia with cortical infarction. METHODS Using a three vessel occlusion model of focal cerebral ischemia combined with bilateral microdialysis, hydroxylation of 4-hydroxybenzoate (4HB) was continuously monitored in both hemispheres in either the lateral striatum or frontoparietal cortex. The ischemia protocol consisted of one hour equilibration, 30 min of three vessel occlusion, then release of the contralateral common carotid artery (CCA) for 2.5 h. RESULTS Induction of ischemia resulted in a 30-fold increase in dopamine release in the lateral striatum. Compared to the nonischemic striatum, the ratio of the hydroxylation product 3,4-dihydroxybenzoate (34DHB) to 4HB (trapping agent) in the ipsilateral striatum increased significantly 30 min after ischemia induction. In contrast, during the 30 min of three vessel occlusion there was no increase in the ratio in the cortex. Following the release of the contralateral CCA, the ratio from the ischemic cortex increased significantly compared to sham-operated animals. However, under all circumstances, the 34DHB/4HB ratio was greater in the striatum than in the cortex. CONCLUSION The increase in the 34DHB/4HB ratio in the lateral striatum coincides with the increased dopamine release suggesting a role for dopamine oxidation in the increased production of hydroxyl radicals. The significant increase in the ratio from the ischemic cortex compared to that from the sham-operated animals is consistent with increased oxidative stress induced by ischemia. However, the lower 34DHB/4HB ratio in the cortex which does not receive dopaminergic innervation compared to the striatum suggests a different mechanism for hydroxyl radical production. Such an alternate mechanism may represent a more toxic oxidative insult that contributes to infarction.
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Montgomery J, Ilg T, Thompson JK, Kobe B, Handman E. Identification and predicted structure of a leucine-rich repeat motif shared by Leishmania major proteophosphoglycan and Parasite Surface Antigen 2. Mol Biochem Parasitol 2000; 107:289-95. [PMID: 10779605 DOI: 10.1016/s0166-6851(00)00186-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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93
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Montgomery J. BDJ readership survey. Br Dent J 2000. [DOI: 10.1038/sj.bdj.4800440a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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94
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Abstract
Over the summer, BDJ readers were surveyed about the BDJ as part of a series of BDJ surveys conducted since 1992. As well as assessing general views about the BDJ, the survey also aimed to discover how successful the 1998 BDJ redesign had been in incorporating reader's views from earlier surveys. The findings from the 1999 survey showed that the BDJ and BDA News continue to be the most read dental publications. Readers turn to the BDJ before any other UK dental journal for finding a job and reports on research. The full results of the survey are reported below.
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95
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Davignon I, Catalina MD, Smith D, Montgomery J, Swantek J, Croy J, Siegelman M, Wilkie TM. Normal hematopoiesis and inflammatory responses despite discrete signaling defects in Galpha15 knockout mice. Mol Cell Biol 2000; 20:797-804. [PMID: 10629036 PMCID: PMC85196 DOI: 10.1128/mcb.20.3.797-804.2000] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Galpha15 activates phospholipase Cbeta in response to the greatest variety of agonist-stimulated heptahelical receptors among the four Gq class G-protein alpha subunits expressed in mammals. Galpha15 is primarily expressed in hematopoietic cells in fetal and adult mice. We disrupted the Galpha15 gene by homologous recombination in embryonic stem cells to identify its biological functions. Surprisingly, hematopoiesis was normal in Galpha15(-/-) mice, Galpha15(-/-) Galphaq(-/-) double-knockout mice (which express only Galpha11 in most hematopoietic cells), and Galpha11(-/-) mice, suggesting functional redundancy in Gq class signaling. Inflammatory challenges, including thioglycolate-induced peritonitis and infection with Trichinella spiralis, stimulated similar responses in Galpha15(-/-) adults and wild-type siblings. Agonist-stimulated Ca(2+) release from intracellular stores was assayed to identify signaling defects in primary cultures of thioglycolate-elicited macrophages isolated from Galpha15(-/-) mice. C5a-stimulated phosphoinositide accumulation and Ca(2+) release was significantly reduced in Galpha15(-/-) macrophages. Ca(2+) signaling was abolished only in mutant cells pretreated with pertussis toxin, suggesting that the C5a receptor couples to both Galpha15 and Galphai in vivo. Signaling evoked by other receptors coupled by Gq class alpha subunits appeared normal in Galpha15(-/-) macrophages. Despite discrete signaling defects, compensation by coexpressed Gq and/or Gi class alpha subunits may suppress abnormalities in Galpha15-deficient mice.
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Ste-Marie L, Vachon L, Bémeur C, Lambert J, Montgomery J. Local striatal infusion of MPP+ does not result in increased hydroxylation after systemic administration of 4-hydroxybenzoate. Free Radic Biol Med 1999; 27:997-1007. [PMID: 10569632 DOI: 10.1016/s0891-5849(99)00170-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In vivo bilateral microdialysis in the rat striatum was used to investigate hydroxyl radical formation under basal conditions and after intrastriatal administration of the neurotoxin, 1-methyl-4-phenylpyridinium (MPP+). After a short equilibration period, 4-hydroxybenzoate (4HBZ), which scavenges hydroxyl radicals to produce 3,4-dihydroxybenzoate (34DHB), was injected intraperitoneally 15 min before infusion of MPP+. To evaluate the enzymatic contribution to hydroxyl radical formation, two other series of microdialyses were performed following administration of monoamine oxidase B inhibitors, either 1-deprenyl (selegiline) or MDL 72,974A [(E)-2-(4-fluorophenethyl)-3-fluoroallylamine hydrochloride]. Microdialysate samples were analyzed by high-performance liquid chromatography for catecholamines, 3,4-dihydroxyphenylacetate (DOPAC), homovanillate (HVA), along with the hydroxyl radical adduct, 34DHB and its precursor, 4HBZ. MPP+ administration resulted in a massive release of dopamine along with a decrease in DOPAC and HVA in all three groups. A striking effect in all three groups was noted in which MPP+ resulted in a decrease in interstitial 4HBZ to < 50% of the non-MPP+ -treated side. In absolute terms, the amount of 34DHB produced was low but similar in all three groups, even after unilateral MPP+ infusion. When 34DHB was normalized to 4HBZ release to account for differences in precursor availability, there were no significant differences in the 34DHB/4HBZ ratios either with or without MAO inhibitor treatment or after local MPP+ infusion. Systemic 4HBZ administration appears to result predominantly in intra-cellular sampling of hydroxyl radicals which produces different results from local infusion of trapping agents such as salicylate.
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Ilg T, Montgomery J, Stierhof YD, Handman E. Molecular cloning and characterization of a novel repeat-containing Leishmania major gene, ppg1, that encodes a membrane-associated form of proteophosphoglycan with a putative glycosylphosphatidylinositol anchor. J Biol Chem 1999; 274:31410-20. [PMID: 10531342 DOI: 10.1074/jbc.274.44.31410] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leishmania parasites secrete a variety of proteins that are modified by phosphoglycan chains structurally similar to those of the cell surface glycolipid lipophosphoglycan. These proteins are collectively called proteophosphoglycans. We report here the cloning and sequencing of a novel Leishmania major proteophosphoglycan gene, ppg1. It encodes a large polypeptide of approximately 2300 amino acids. The N-terminal domain of approximately 70 kDa exhibits 11 imperfect amino acid repeats that show some homology to promastigote surface glycoproteins of the psa2/gp46 complex. The large central domain apparently consists exclusively of approximately 100 repetitive peptides of the sequence APSASSSSA(P/S)SSSSS(+/-S). Gene fusion experiments demonstrate that these peptide repeats are the targets of phosphoglycosylation in Leishmania and that they form extended filamentous structures reminiscent of mammalian mucins. The C-terminal domain contains a functional glycosylphosphatidylinositol anchor addition signal sequence, which confers cell surface localization to a normally secreted Leishmania acid phosphatase, when fused to its C terminus. Antibody binding studies show that the ppg1 gene product is phosphoglycosylated by phosphoglycan repeats and cap oligosaccharides. In contrast to previously characterized proteophosphoglycans, the ppg1 gene product is predominantly membrane-associated and it is expressed on the promastigote cell surface. Therefore this membrane-bound proteophosphoglycan may be important for direct host-parasite interactions.
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98
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Budd P, Montgomery J, Cox A, Krause P, Barreiro B, Thomas RG. The distribution of lead within ancient and modern human teeth: implications for long-term and historical exposure monitoring. THE SCIENCE OF THE TOTAL ENVIRONMENT 1998; 220:121-136. [PMID: 9810721 DOI: 10.1016/s0048-9697(98)00244-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The preservation of lead within human tissue makes it possible to monitor long-term exposure to the element and to model changing sources of lead pollution throughout the lifetime of an individual. Dental tissues have recently been shown to be particularly useful for this purpose. Enamel, for instance, forms at known stages of life and is chemically stable in vivo whereas dentine is remodelled in a predictable fashion. The relative stability of enamel is reflected in its excellent post-mortem preservation. This raises the possibility of using historical or archaeological material to reconstruct long-term trends and establish baseline data relating to exposure among pre-industrial or even prehistoric populations. The use of archaeological material is currently problematic, however, because of the site-specific nature of diagenesis and incomplete understanding of its chemistry, particularly in respect of lead uptake into dental tissue from the burial environment. A detailed study of lead distribution within both ancient and modern human teeth is presented. Conclusions are drawn on the pattern of lead distribution resulting from tissue formation and the manner of its alteration in the burial environment. In particular, attention is drawn to a consistent enrichment of lead within the outer 30 microns of the enamel of both ancient and modern teeth which appears to be unrelated to diagenesis. The implications for current approaches to long-term monitoring and for the reconstruction of historical and archaeological exposure patterns are discussed.
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Keenan SP, Montgomery J, Chen LM, Esmail R, Inman KJ, Sibbald WJ. Ventilatory care in a selection of Ontario hospitals: bigger is not necessarily better! Critical Care Research Network (CCR-Net). Intensive Care Med 1998; 24:946-52. [PMID: 9803331 DOI: 10.1007/s001340050694] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
OBJECTIVE To determine whether there is variability in the structure and process of ventilatory care in intensive care units (ICUs) of the hospitals of Southwestern Ontario. DESIGN Self-administered questionnaire-based survey. SETTING ICUs of selected community and teaching hospitals of Southwestern Ontario. PARTICIPANTS Head of respiratory therapy service of respective hospitals; in those hospitals without respiratory therapists, the ICU nurse manager. INTERVENTION Self-administered questionnaire. OUTCOME MEASURE(S) The availability of different models of ventilators and respiratory therapist and physician coverage were assessed. In addition, the use of clinical practice guidelines, respiratory therapists, and the nursing role in ventilatory care were determined. RESULTS In general, the structure of ventilatory care, including availability of different modes of ventilation, and coverage by respiratory therapists and physicians was more comprehensive in larger hospitals. However, the availability of some modes of ventilation varied more than expected among hospitals of comparable size. Similarly, variability in the process of ventilatory care, defined by the availability of clinical practice guidelines and the roles of respiratory therapists varied both within and among hospitals of different size. CONCLUSIONS The structure and process of ventilatory care in this sample of Southwestern Ontario ICUs was found to be variable. Not all this variability could be accounted for by hospital size, suggesting a potential for improvement in overall ventilatory care. Further study is required before any specific recommendations can be considered.
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Coombs S, Mogdans J, Halstead M, Montgomery J. Transformation of peripheral inputs by the first-order lateral line brainstem nucleus. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 1998; 182:606-26. [PMID: 9579053 DOI: 10.1007/s003590050207] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Extracellular recording techniques were used to record the responses of medial nucleus cells and posterior lateral line nerve fibers in mottled sculpin, Cottus bairdi, and goldfish, Carassius auratus, to a 50-Hz dipole source (vibrating sphere). Responses were characterized in terms of (1) receptive fields that relate responsiveness (spike rate and phase-locking) to the location of the source along the length of the fish, (2) input-output functions that relate responsiveness to vibration amplitude for a fixed source location, and (3) peri-stimulus time histograms that relate responsiveness to time during a sustained period of vibration. Relative to posterior lateral line nerve fibers, medial nucleus cells in both species were similar in showing (1) lower spontaneous and evoked rates of spike activity, (2) greater degrees of adaptation, (3) greater heterogeneity in all response characteristics, and (4) evidence for inhibitory/excitatory interactions. Whereas receptive fields of nerve fibers in both species faithfully reflect both pressure gradient amplitudes (with rate changes) and directions (with phase-angle changes) in the stimulus field, receptive fields of medial nucleus were more difficult to relate to the stimulus field, Some, but not all, receptive fields could be modeled with excitatory center/inhibitory surround and inhibitory center/excitatory surround organizations.
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