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Prevalence of multidrug resistance in Pseudomonas spp. isolated from wild bird feces in an urban aquatic environment. Ecol Evol 2021; 11:14303-14311. [PMID: 34707856 PMCID: PMC8525170 DOI: 10.1002/ece3.8146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 08/25/2021] [Accepted: 09/01/2021] [Indexed: 01/18/2023] Open
Abstract
Antimicrobial resistance (AMR) has been detected in the microbiota of wildlife, yet little is known about the origin and impact within the ecosystem. Due to the shortage of nonepizootic surveillance, there is limited understanding of the natural prevalence and circulation of AMR bacteria in the wild animal population, including avian species. In this surveillance study, feces from wild birds in proximity to the River Cam, Cambridge, England, were collected and Pseudomonas spp. were isolated. Of the 115 samples collected, 24 (20.9%; 95% CI, 12.6%‒29.2%) harbored Pseudomonas spp. of which 18 (75%; 95% CI, 58%‒92%) had a multiple antibiotic resistance (MAR) index greater than 0.2. No Pseudomonas spp. isolate in this study was pansusceptible. Resistance was found among the 24 isolates against ciprofloxacin (87.5%; 95% CI, 74.3%‒100%) and cefepime (83.3%; 95% CI, 68.4%‒98.2%), both of which are extensively used to treat opportunistic Pseudomonas spp. infections. The prevalence of Pseudomonas spp. in the wild bird feces sampled during this study is greater than previous, similar studies. Additionally, their multidrug resistance profile provides insight into the potential risk for ecosystem contamination. It further highlights the importance of a One Health approach, including ongoing surveillance efforts that help to develop the understanding of how wildlife, including avifauna, may contribute and disperse AMR across the ecosystem.
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Multiple Origins and Specific Evolution of CRISPR/Cas9 Systems in Minimal Bacteria ( Mollicutes). Front Microbiol 2019; 10:2701. [PMID: 31824468 PMCID: PMC6882279 DOI: 10.3389/fmicb.2019.02701] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 11/07/2019] [Indexed: 12/13/2022] Open
Abstract
CRISPR/Cas systems provide adaptive defense mechanisms against invading nucleic acids in prokaryotes. Because of its interest as a genetic tool, the Type II CRISPR/Cas9 system from Streptococcus pyogenes has been extensively studied. It includes the Cas9 endonuclease that is dependent on a dual-guide RNA made of a tracrRNA and a crRNA. Target recognition relies on crRNA annealing and the presence of a protospacer adjacent motif (PAM). Mollicutes are currently the bacteria with the smallest genome in which CRISPR/Cas systems have been reported. Many of them are pathogenic to humans and animals (mycoplasmas and ureaplasmas) or plants (phytoplasmas and some spiroplasmas). A global survey was conducted to identify and compare CRISPR/Cas systems found in the genome of these minimal bacteria. Complete or degraded systems classified as Type II-A and less frequently as Type II-C were found in the genome of 21 out of 52 representative mollicutes species. Phylogenetic reconstructions predicted a common origin of all CRISPR/Cas systems of mycoplasmas and at least two origins were suggested for spiroplasmas systems. Cas9 in mollicutes were structurally related to the S. aureus Cas9 except the PI domain involved in the interaction with the PAM, suggesting various PAM might be recognized by Cas9 of different mollicutes. Structure of the predicted crRNA/tracrRNA hybrids was conserved and showed typical stem-loop structures pairing the Direct Repeat part of crRNAs with the 5' region of tracrRNAs. Most mollicutes crRNA/tracrRNAs showed G + C% significantly higher than the genome, suggesting a selective pressure for maintaining stability of these secondary structures. Examples of CRISPR spacers matching with mollicutes phages were found, including the textbook case of Mycoplasma cynos strain C142 having no prophage sequence but a CRISPR/Cas system with spacers targeting prophage sequences that were found in the genome of another M. cynos strain that is devoid of a CRISPR system. Despite their small genome size, mollicutes have maintained protective means against invading DNAs, including restriction/modification and CRISPR/Cas systems. The apparent lack of CRISPR/Cas systems in several groups of species including main pathogens of humans, ruminants, and plants suggests different evolutionary routes or a lower risk of phage infection in specific ecological niches.
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European surveillance of emerging pathogens associated with canine infectious respiratory disease. Vet Microbiol 2017; 212:31-38. [PMID: 29173585 PMCID: PMC7117498 DOI: 10.1016/j.vetmic.2017.10.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 10/18/2017] [Accepted: 10/25/2017] [Indexed: 12/31/2022]
Abstract
The largest study of its kind in the field to date, including high-risk kennelled dogs, and for the first time, pet dogs and dogs from other cohorts. A clearly identifiable link between disease and the emerging pathogens: canine respiratory coronavirus and canine pneumovirus. Provides, substantial evidence of CIRD and the circulation of the novel pathogens studied in pet dogs, and dogs from other cohorts. Demonstrates the role and limitations of current vaccine strategies in managing CIRD outbreaks, and the need for including emerging pathogens.
Canine infectious respiratory disease (CIRD) is a major cause of morbidity in dogs worldwide, and is associated with a number of new and emerging pathogens. In a large multi-centre European study the prevalences of four key emerging CIRD pathogens; canine respiratory coronavirus (CRCoV), canine pneumovirus (CnPnV), influenza A, and Mycoplasma cynos (M. cynos); were estimated, and risk factors for exposure, infection and clinical disease were investigated. CIRD affected 66% (381/572) of the dogs studied, including both pet and kennelled dogs. Disease occurrence and severity were significantly reduced in dogs vaccinated against classic CIRD agents, canine distemper virus (CDV), canine adenovirus 2 (CAV-2) and canine parainfluenza virus (CPIV), but substantial proportions (65.7%; 201/306) of vaccinated dogs remained affected. CRCoV and CnPnV were highly prevalent across the different dog populations, with overall seropositivity and detection rates of 47% and 7.7% for CRCoV, and 41.7% and 23.4% for CnPnV, respectively, and their presence was associated with increased occurrence and severity of clinical disease. Antibodies to CRCoV had a protective effect against CRCoV infection and more severe clinical signs of CIRD but antibodies to CnPnV did not. Involvement of M. cynos and influenza A in CIRD was less apparent. Despite 45% of dogs being seropositive for M. cynos, only 0.9% were PCR positive for M. cynos. Only 2.7% of dogs were seropositive for Influenza A, and none were positive by PCR.
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Abstract
Background: The World Health Organisation cites a sedentary lifestyle as one of the top ten causes of morbidity and mortality worldwide.4 A recent, large-scale clinical study showed that brisk walking and vigorous exercise are associated with substantial (and similar) reductions in the incidence of coronary heart disease,6 Current guidelines suggest 10,000 steps per day as an appropriate activity target for healthy adults.7 Aims: This study aims to assess whether doctors are meeting this daily walking target during working-hours, and whether additional out-of-hours exercise is required. Methods: 16 doctors from St. John's Hospital in Livingston (comprising 4 Medical Consultants, 4 Surgical Consultants, 4 Medical PRHOs and 4 Surgical PRHOs) each used a belt-worn pedometer to record all steps made during 5 consecutive day shifts. Stride length and total daily steps were recorded. Steps made out-with working hours were not counted. Total steps and hours worked were recorded at the end of each day. Results: Average daily steps recorded were 7907 (Medical PRHOs), 5068 (Surgical PRHOs), 4822 (Surgical Consultants) and 4647 (Medical Consultants). P values of <0.1 were obtained for the variation in steps between the Medical PRHOs and both the Consultant Surgeons and Consultant Physicians. Distance walked per shift varied from 3.84 (Consultant Physicians) to 6.85 kilometres (Medical PRHOs). Conclusion: Walking at work does provide a substantial proportion of a doctor's recommended daily activity quota. However, it is still necessary to engage in additional, out-of-hours exercise in order to consistently meet the current recommendations for physical exercise.
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Identification of quantitative trait loci (QTL) for resistance to Fusarium crown rot (Fusarium pseudograminearum) in multiple assay environments in the Pacific Northwestern US. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2012; 125:91-107. [PMID: 22366812 PMCID: PMC3351592 DOI: 10.1007/s00122-012-1818-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 02/03/2012] [Indexed: 05/22/2023]
Abstract
Fusarium crown rot (FCR), caused by Fusarium pseudograminearum and F. culmorum, reduces wheat (Triticum aestivum L.) yields in the Pacific Northwest (PNW) of the US by as much as 35%. Resistance to FCR has not yet been discovered in currently grown PNW wheat cultivars. Several significant quantitative trait loci (QTL) for FCR resistance have been documented on chromosomes 1A, 1D, 2B, 3B, and 4B in resistant Australian cultivars. Our objective was to identify QTL and tightly linked SSR markers for FCR resistance in the partially resistant Australian spring wheat cultivar Sunco using PNW isolates of F. pseudograminerarum in greenhouse and field based screening nurseries. A second objective was to compare heritabilities of FCR resistance in multiple types of disease assaying environments (seedling, terrace, and field) using multiple disease rating methods. Two recombinant inbred line (RIL) mapping populations were derived from crosses between Sunco and PNW spring wheat cultivars Macon and Otis. The Sunco/Macon population comprised 219 F(6):F(7) lines and the Sunco/Otis population comprised 151 F(5):F(6) lines. Plants were inoculated with a single PNW F. pseudograminearum isolate (006-13) in growth room (seedling), outdoor terrace (adult) and field (adult) assays conducted from 2008 through 2010. Crown and lower stem tissues of seedling and adult plants were rated for disease severity on several different scales, but mainly on a numeric scale from 0 to 10 where 0 = no discoloration and 10 = severe disease. Significant QTL were identified on chromosomes 2B, 3B, 4B, 4D, and 7A with LOD scores ranging from 3 to 22. The most significant and consistent QTL across screening environments was located on chromosome 3BL, inherited from the PNW cultivars Macon and Otis, with maximum LOD scores of 22 and 9 explaining 36 and 23% of the variation, respectively for the Sunco/Macon and Sunco/Otis populations. The SSR markers Xgwm247 and Xgwm299 flank these QTL and are being validated for use in marker-assisted selection for FCR resistance. This is the first report of QTL associated with FCR resistance in the US.
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VEGF modulates the effects of gonadotropins in granulosa cells. Domest Anim Endocrinol 2010; 38:127-37. [PMID: 19815366 DOI: 10.1016/j.domaniend.2009.08.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Revised: 08/31/2009] [Accepted: 08/31/2009] [Indexed: 11/13/2022]
Abstract
Follicle selection is associated with an increase in the expression of vascular endothelial growth factor (VEGF) and its receptors in granulosa cells, however, the roles of VEGF in regulating the function of these or other non-endothelial cells in the ovary have not been explored in detail. The current study used bovine cell cultures to investigate potential roles of VEGF in the regulation of granulosa cell function during follicle development. Granulosa cells were obtained from morphologically healthy follicles 4 to 8 mm or 9 to 14 mm in diameter (corresponding to diameters before and after the establishment of dominance, respectively, during a bovine follicular wave) and exposed to a range of VEGF concentrations (1 to 100 ng/mL) encompassing concentrations found naturally in bovine dominant follicles. A concentration of VEGF of 1 ng/mL induced significant proliferation of granulosa cells from 4- to 8-mm follicles (P=0.024) and increased the proliferative response of these cells to follicle-stimulating hormone (FSH; P=0.045); whereas higher doses of VEGF had no effect on proliferation (P=0.9). Treatment with VEGF induced an overall increase in mean extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation (P=0.02). In contrast, VEGF, alone or in combination with FSH, had no effect on expression of the steroidogenic enzyme, CYP11A1, by cells from 4- to 8-mm follicles (P=0.9). Granulosa cells from 9- to 14-mm follicles responded to 1 ng/mL VEGF with an increase in expression of the ovulation-associated gene, PTGS2 (P=0.003) but higher VEGF doses had no effect (P=0.9). The PTGS2 response to 1 ng/mL VEGF was similar to that induced by treatment with luteinizing hormone (LH). Interestingly, the stimulatory effects of LH on ERK1/2 phosphorylation (P=0.003) and PTGS2 expression (P<0.01) in granulosa cells from 9- to 14-mm follicles were abolished (P=0.2) by specific chemical inhibition of VEGF receptor 2 (VEGFR2). These results suggest novel and important roles of VEGF and its receptor, VEGFR2, in mediating and/or enhancing the effects of gonadotropins in granulosa cells.
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Abstract
Most of our understanding of the pathogenesis of the unconventional slow infections comes from studies of experimental scrapie in mice and hamsters. After injection by non-neural peripheral routes, pathogenesis necessarily involves the lymphoreticular system (LRS) before the central nervous system (CNS). Available evidence indicates haematogenous spread from the site of injection to the scrapie replication sites in the LRS; later, infection spreads along visceral autonomic nerves from the LRS to the thoracic spinal cord, and thence to brain. The cells in the LRS which are important to scrapie pathogenesis are long lived. Neuroinvasion and spread of infection within the CNS probably involve neuronal pathways. We suggest that disease develops after infection has reached certain clinical target areas in the CNS but only when scrapie replication there has caused sufficient functional damage. Restriction of the replication process in both LRS and CNS is indicated by the occurrence of plateau concentrations of infectivity, especially in some long incubation scrapie models. A remarkable feature of these is that both neuroinvasion and clinical disease occur long after infectivity plateaux have been reached in the LRS and CNS, respectively. We propose that the slowness of scrapie is related to (1) limitations of cell-to-cell spread of infection from LRS to CNS, and (2) limitations on spread between neurons, coupled with restrictions on replication in brain.
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Sick notes, general practitioners, emergency departments and fracture clinics. Emerg Med J 2007; 24:31-2. [PMID: 17183039 PMCID: PMC2658149 DOI: 10.1136/emj.2006.042960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND General practitioner waiting times are increasing. The two national surveys regarding general practice showed that the number of patients waiting for >or=2 days for an appointment rose from 63% to 72% between 1998 and 2002, with 25% waiting for >or=4 days. The Department of Health recognised that many patients discharged from hospitals and outpatient clinics required to visit their general practitioner for the sole purpose of obtaining a sick note. The report entitled Making a difference: reducing general practitioner paperwork estimated that 518 000 appointments (and 42 000 GP h) could be saved by ensuring that these patients were issued with a sick note directly from hospital rather than being referred to their general practitioner. This practice was to be adopted from July 2001 and included patients discharged from wards as well as those seen in outpatient departments. METHOD 50 emergency departments and fracture clinics in Scotland and England were contacted to assess whether these guidelines had been adopted. Only hospitals with both accident and emergency and fracture clinics were included; nurse-led and paediatric departments were excluded. RESULTS Of the 25 Scottish emergency hospitals contacted, 4 (16%) accident and emergency departments and 8 (32%) fracture clinics issued sick notes. This was compared with 5 of 25 (20%) accident and emergency departments and 12 of 25 (48%) fracture clinics in England. Four Scottish and five English accident and emergency departments stated that it was policy to give sick notes, three Scottish and four English departments said that it was policy not to give them and the rest (72% in Scotland and 64% in England) stated that they had no clear policy but "just don't give them". CONCLUSION The 2001 guidance from the joint Cabinet Office/Department of Health has not been fully incorporated into standard practice in Scotland and England. If all emergency departments and fracture clinics were to issue sick notes to patients requiring >7 days absence from work, this could reduce general practitioner consultations and improve waiting times.
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Development of an in vivo Himar1 transposon mutagenesis system for use in Streptococcus equi subsp. equi. FEMS Microbiol Lett 2005; 238:401-9. [PMID: 15358426 DOI: 10.1016/j.femsle.2004.08.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2004] [Revised: 08/02/2004] [Accepted: 08/03/2004] [Indexed: 11/22/2022] Open
Abstract
Streptococcus equi subsp. equi is the causative agent of the equine disease strangles. In this study we describe the development of an in vivo Himar1 transposon system for the random mutagenesis of S. equi and, potentially, other Gram-positive bacteria. We demonstrate efficient and random transposition of a modified mini-transposon onto the chromosome by Southern blot analysis and insertion site sequencing. Non-haemolytic mutants were isolated at a frequency of 0.2%, and acapsular mutants at a frequency of 0.04%. Taken together, these data demonstrate that in vivo Himar1 mutagenesis can be used for genomic-scale mutational analysis of S. equi, and is likely to be applicable to the study of other streptococci.
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Development of an in vivo Himar1transposon mutagenesis system for use in Streptococcus equisubsp. equi. FEMS Microbiol Lett 2004. [DOI: 10.1111/j.1574-6968.2004.tb09782.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Endothelin-1 during and after cardiopulmonary bypass: association to graft sensitivity and postoperative recovery. J Thorac Cardiovasc Surg 2001; 122:358-64. [PMID: 11479510 DOI: 10.1067/mtc.2001.114936] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Our objectives are 2-fold: (1) to serially measure the release of endothelin and graft-conduit endothelin sensitivity during and after coronary artery bypass grafting and (2) to define potential relationships of changes in endothelin levels to perioperative parameters. METHODS Endothelin plasma content was measured in patients (n = 105) undergoing bypass grafting from select vascular compartments before operations and at specific intervals up to 24 hours postoperatively. Endothelin sensitivity was determined in isolated internal thoracic artery segments. RESULTS Systemic arterial and pulmonary arterial endothelin levels were increased by approximately 50% immediately after bypass grafting and increased by another 85% during the first 24 hours postoperatively. Endothelin levels were highest in patients with prolonged ventilatory requirements and extended stays in the intensive care unit (10.2 +/- 0.8 vs 13.2 +/- 1.1 fmol/mL, P =.02, and 9.8 +/- 0.7 vs 13.9 +/- 1.2 fmol/mL, P =.01, respectively. Endothelin sensitivity of the internal thoracic artery was increased in patients requiring prolonged vasodilator support with nitroglycerin. CONCLUSIONS Systemic and pulmonary arterial endothelin levels remained increased for at least 24 hours postoperatively. Prolonged pharmacologic management and increased intensive care unit stay were associated with increased systemic endothelin release and heightened graft-conduit sensitivity to endothelin.
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Endothelin receptor subtype A blockade selectively reduces pulmonary pressure after cardiopulmonary bypass. J Thorac Cardiovasc Surg 2001; 122:365-70. [PMID: 11479511 DOI: 10.1067/mtc.2001.114938] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND The bioactive peptide endothelin-1 is elevated during and after cardiopulmonary bypass and exerts cardiovascular effects through its 2 receptor subtypes, endothelin-1A and endothelin-1B. Increased endothelin-1A receptor stimulation after cardiopulmonary bypass can cause increased pulmonary vascular resistance and modulate myocardial contractility. However, whether and to what degree selective endothelin-1A blockade influences these parameters in the postbypass setting is not completely understood. OBJECTIVES Our objective was to measure left ventricular function and hemodynamics in a porcine model of cardiopulmonary bypass after selective blockade of endothelin-1A. METHODS Adult pigs (n = 23) underwent 90 minutes of cardiopulmonary bypass and were randomized 30 minutes after bypass to receive a selective endothelin-1A antagonist (TBC 11251, 10 mg/kg; n = 13) or saline vehicle (n = 10). RESULTS After bypass and before randomization, pulmonary vascular resistance rose nearly 4-fold, and left ventricular preload recruitable stroke work fell to one third of baseline values (both P <.05). In the vehicle group pulmonary vascular resistance continued to rise, and preload recruitable stroke work remained reduced. However, after endothelin-1A blockade, the rise in pulmonary vascular resistance was significantly blunted compared with that in the vehicle group. Moreover, the reduction in pulmonary vascular resistance with endothelin-1A blockade was achieved without a significant change in systemic perfusion pressures. CONCLUSIONS The present study demonstrated that increased activity of the endothelin-1A receptor likely contributes to alterations in pulmonary vascular resistance in the postbypass setting. Selective endothelin-1A blockade may provide a means to selectively decrease pulmonary vascular resistance without significant effects on systemic hemodynamics.
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Abstract
BACKGROUND Although end-stage dilated cardiomyopathy (DCM) is characterized by defects in beta-adrenergic receptor (beta-AR) activity and increased endothelin-1 (ET-1), possible interactions between these 2 systems remain to be defined. Accordingly, the goal of this study was to determine the effects of ET receptor activation on beta-AR signaling through measurement of cyclic adenosine monophosphate (cAMP) in normal and DCM myocardium. METHODS AND RESULTS Myocardial sarcolemmal preparations were prepared from normal human (n = 6), dilated cardiomyopathic (n = 10), and ischemic cardiomyopathic (ICM, n = 10) tissue. Basal cAMP production was measured in the presence of ET-1 alone (10(-6) to 0(-9) mol/L) as well as after (-)isoproterenol (10(-6) to 10(-2) mol/L) or forskolin (0.05 to 30.0 micromol/L) stimulation. beta-AR and ET receptor profiles were determined by radiolabeled ligand assays. ET-1 inhibited basal cAMP production in all preparations in a concentration-dependent manner. However, beta-AR-stimulated cAMP production by either isoproterenol or forskolin was not significantly affected by ET-1. beta-AR receptor density was reduced, and a selective reduction of the ET(B) receptor occurred in both forms of DCM. CONCLUSIONS Under basal conditions, ET receptor stimulation reduced cAMP levels, which may influence contractility, particularly with DCM.
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Temporal endothelin dynamics of the myocardial interstitium and systemic circulation in cardiopulmonary bypass. J Thorac Cardiovasc Surg 2000; 120:864-71. [PMID: 11044311 DOI: 10.1067/mtc.2000.109700] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Increased systemic levels of the bioactive peptide endothelin 1 during and after cardioplegic arrest and cardiopulmonary bypass have been well documented. However, endothelin 1 is synthesized locally, and therefore myocardial endothelin 1 production during and after cardiopulmonary bypass remains unknown. METHODS Pigs (n = 11) were instrumented for cardiopulmonary bypass, and cardioplegic arrest was initiated. Myocardial interstitial and systemic arterial levels of endothelin 1 were measured before cardiopulmonary bypass, throughout bypass and cardioplegic arrest (90 minutes), and up to 90 minutes after separation from bypass. Myocardial interstitial endothelin 1 was determined by microdialysis and radioimmunoassay. RESULTS Baseline myocardial endothelin 1 levels were higher than systemic endothelin 1 levels (25.6 +/- 6.7 vs 8.3 +/- 1.1 fmol/mL, P <.05). With the onset of bypass, myocardial endothelin 1 increased by 327% +/- 92% from baseline (P <.05), which preceded the increase in systemic endothelin 1 levels. CONCLUSION Myocardial compartmentalization of endothelin 1 exists in vivo. Cardiopulmonary bypass and cardioplegic arrest induce temporal differences in endothelin 1 levels within the myocardial interstitium and systemic circulation, which, in turn, may influence left ventricular function in the postbypass period.
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Temporal synthesis and release of endothelin within the systemic and myocardial circulation during and after cardiopulmonary bypass: relation to postoperative recovery. J Cardiothorac Vasc Anesth 2000; 14:540-5. [PMID: 11052435 DOI: 10.1053/jcan.2000.9451] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To determine endothelin levels in arterial, pulmonary, and myocardial vascular compartments in patients undergoing coronary artery bypass graft surgery and to examine the influence of endothelin on postoperative recovery. DESIGN Prospective, clinical study. SETTING University hospital. PARTICIPANTS Fifty patients undergoing elective coronary artery bypass graft surgery. INTERVENTIONS Endothelin plasma content (fmol/mL) was measured in 50 patients undergoing coronary revascularization from various vascular compartments before surgery and at specific intervals up to 24 hours postoperatively. MEASUREMENTS AND MAIN RESULTS Myocardial endothelin gradient (coronary sinus - aorta) was calculated before cardiopulmonary bypass (CPB), at release of the aortic cross-clamp, immediately after CPB, and 0.5 hour after CPB. The requirement for inotropic therapy and duration of patient stay in the intensive care unit were determined. Systemic and pulmonary endothelin levels were increased by >80% immediately after CPB when compared with preoperative values and increased again by approximately 60% during the first 24 hours postoperatively (p < 0.05). The myocardial endothelin gradient was reversed after CPB, indicating myocardial production of endothelin (pre-CPB, -0.72+/-0.39 fmol/mL v 0.5 hour post-CPB, 0.60+/-0.49 fmol/mL; p < 0.05). Longer intensive care unit times (>28 hours) were associated with higher systemic endothelin levels when compared with shorter times (<18 hours) (16.30+/-1.33 fmol/mL v 9.81+/-1.67 fmol/mL; p < 0.05). Patients with higher endothelin levels 6 hours postoperatively had greater inotropic requirements during the intensive care unit period. CONCLUSION Endothelin levels after CPB remained persistently increased for at least 24 hours after surgery and were associated with increased myocardial production of endothelin. These results suggest that the increased endothelin observed in the early postoperative period may contribute to a complex recovery from coronary artery bypass graft surgery.
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Abstract
Increased plasma levels of endothelin-1 (ET-1) have been identified in congestive heart failure (CHF), but local myocardial interstitial ET-1 levels and the relation to determinants of ET-1 synthesis remain to be defined. Accordingly, myocardial interstitial ET-1 levels and myocyte endothelin-converting enzyme (ECE)-1 activity and expression with the development of CHF were examined. Pigs were instrumented with a microdialysis system to measure myocardial interstitial ET-1 levels with pacing CHF (240 beats/min, 3 wk; n = 9) and in controls (n = 14). Plasma ET-1 was increased with CHF (15 +/- 1 vs. 9 +/- 1 fmol/ml, P < 0.05) as was total myocardial ET-1 content (90 +/- 15 vs. 35 +/- 5 fmol/g, P < 0.05). Paradoxically, myocardial interstitial ET-1 was decreased in CHF (32 +/- 4 vs. 21 +/- 2 fmol/ml, P < 0.05), which indicated increased ET-1 uptake by the left ventricular (LV) myocardium with CHF. In isolated LV myocyte preparations, ECE-1 activity was increased by twofold with CHF (P < 0.05). In LV myocytes, both ECE-1a and ECE-1c mRNAs were detected, and ECE-1a expression was upregulated fivefold in CHF myocytes (P < 0.05). In conclusion, this study demonstrated compartmentalization of ET-1 in the myocardial interstitium and enhanced ET-1 uptake with CHF. Thus a local ET-1 system exists at the level of the myocyte, and determinants of ET-1 biosynthesis are selectively regulated within this myocardial compartment in CHF.
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Abstract
A F2 population derived from a cross between European Large White and Chinese Meishan pigs was established in order to study the genetic basis of breed differences for growth and fat traits. Chromosome 4 was chosen for initial study as previous work had revealed quantitative trait loci (QTLs) on this chromosome affected growth and fat traits in a Wild Boar x Large White cross. Individuals in the F2 population were typed for nine markers spanning a region of approximately 124 CM. We found evidence for QTLs affecting growth between weaning and the end of test (additive effect: 43.4 g/day) and fat depth measured in the mid-back position (additive effect: 1.82 mm). There was no evidence of interactions between the QTLs and sex, grandparents or F1 sires, suggesting that the detected QTLs were fixed for alternative alleles in the Meishan and Large White breeds. Comparison of locations suggests that these QTLs could be the same as those found in the Wild Boar x Large White cross.
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Taoism: the way. JOURNAL OF THE MEDICAL ASSOCIATION OF GEORGIA 1998; 87:300-2. [PMID: 9868877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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Detection of PCR products from Mycobacterium avium subspecies Paratuberculosis using oligonucleotides containing multiple 2,4-dinitrophenyl reporter groups. BIOMEDICAL PEPTIDES, PROTEINS & NUCLEIC ACIDS : STRUCTURE, SYNTHESIS & BIOLOGICAL ACTIVITY 1997; 1:17-20. [PMID: 9346864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A pool of five oligonucleotides has been used to detect the pathogenic organism Mycobacterium avium subspecies paratuberculosis in PCR-amplified DNA from ruminants. The oligonucleotides were labelled at the 5'-end with three dinitrophenyl reporter groups and hybridised to the target DNA, which was fixed to a nylon membrane by ultraviolet irradiation. Colourimetric detection of the PCR product was carried out using an anti-DNP antibody conjugated to horseradish peroxidase or to alkaline phosphatase. Detection with alkaline phosphatase was more sensitive than with horseradish peroxidase but, in both cases, the PCR product could be easily detected. The DNP labelling system offers an economic and effective alternative to biotin, digoxigenin or fluorescein for the detection of PCR-amplified DNA.
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Abstract
The theories of two nurse visionaries, Rosemarie Rizzo Parse and Jean Watson, are examined for areas of agreement and notable differences. Watson and Parse reject (or hold seriously suspect) traditional, positivistic methods of studying human behaviour and posit their theories as alternatives to the totality paradigm. Since both of these theories, Parse's theory of human becoming and Watson's theory of transpersonal care, borrow heavily from existential phenomenology, major tenets of this philosophic perspective are outlined. Each theory is then described with emphasis on anchoring motifs, concepts, and principles. Next both theories are analysed and critiqued simultaneously. Finally, the theories are applied to a case study with the intent of maximizing their mutual strengths and diminishing their limitations. Coalescence of compatible theories is recommended as a way of enhancing the application of nursing knowledge in practice.
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No association between p53 status and alpha-particle-induced chromosomal instability in human lymphoblastoid cells. Int J Radiat Biol 1996; 69:167-74. [PMID: 8609452 DOI: 10.1080/095530096145995] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Previous work has demonstrated that alpha-particle irradiation of primary human bone marrow cells leads to the transmission of chromosomal instability in the descendants of the irradiated cell, although there is some interindividual variation. We have extended these studies to human EBV-transformed lymphoblastoid cell lines in order to establish an in vitro model system. The five cell lines analyzed, including one from a Fanconi anaemia patient, exhibited high levels of persistent chromatid aberrations up to approximately 40 cell generations after alpha-irradiation. The p53 status of the cell lines was defined according to whether cellular p53 levels were induced by irradiation, translocated to the nucleus and were able to bind a p53 DNA consensus recognition sequence in vitro. Together with the primary bone marrow cell studies, we conclude that alpha-particle induced chromosomal instability is independent of the p53 status of the cell as defined in these studies.
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Abstract
Factor analysis of FIRO-B data obtained from new software product teams had led to a reformulation of Schutz's ideas on team compatibility. The concept of Group-Warmth as a derivative of the FIRO-B Inclusion and Affection scales was developed and shown to be related to the commercial effectiveness of teams. In a like manner, the FIRO-B constructs of Control-Expressed and Control-Wanted were explored through concurrent factor analysis of 16 PF data. A new interpretation has been given to both FIRO-B Control scales, namely, Assertive-Impulsive.
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Hepato-biliary and renal excretion in mice of charged and neutral gadolinium complexes of cyclic tetra-aza-phosphinic and carboxylic acids. Magn Reson Imaging 1993; 11:761-70. [PMID: 8371632 DOI: 10.1016/0730-725x(93)90194-i] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Tissue distribution of 21 new 157/153Gd complexes was measured at 5 min and 24 hr after an intravenous injection into mice. A complex was judged to be stable in vivo when the percentage of 153Gd retained in the liver and skeleton at 24 hr was comparable with that of 153Gd(DOTA)-. Complexes varied in net charge and lipophilicity and 20 were phosphinic or carboxylic acid derivatives of tetra-aza-cyclo-dodecane. Three anionic, lipophilic complexes were cleared predominantly by the hepato-biliary pathway and were stable in vivo. The remaining 18 complexes were cleared mainly by the kidneys. Of these 18, 1 anionic, 8 neutral, and 3 cationic complexes were stable in vivo. These findings augur well for the future of hepato-biliary and general purpose Gd contrast enhancing agents for MRI.
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Abstract
Tumour uptake of the inert, neutral complex 67Ga-9N3 and the tumour:blood concentration ratio (1,4,7,triazacyclononane-1,4,7, triacetic acid) were measured in mice bearing xenografts of the human melanotic melanoma HX118. Between 1 and 4 h after the injection the tumour:blood ratio increased from 3.5 to 21 and the concentration of 67Ga-9N3 in the tumour decreased from 0.43 to 0.13% g-1. During the first 24 h the concentration of 67Ga-9N3 in the tumour exceeded that in all other tissues except the liver and kidneys. The tumour:blood ratio and tissue distribution of 67Ga-9N3 at 4 h were compared with those of four other complexes. The results indicated that of the five complexes 67Ga-9N3 would be the most suitable for tumour imaging at early times after administration. Imaging would not be restricted to gamma emitting 67Ga as there is also the possibility of using the 9N3 ligand to bind 111In for single photon emission computed tomography (SPECT), 68Ga for positron emission tomography (PET) or even stable Ga for direct in vivo nuclear magnetic resonance (NMR) detection.
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The in vivo release of 90Y from cyclic and acyclic ligand-antibody conjugates. INTERNATIONAL JOURNAL OF RADIATION APPLICATIONS AND INSTRUMENTATION. PART B, NUCLEAR MEDICINE AND BIOLOGY 1991; 18:469-76. [PMID: 1917516 DOI: 10.1016/0883-2897(91)90107-v] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Yttrium binding ligands DOTA, caDTPA and CT-DTPA were each conjugated to monoclonal antibody B72.3, labelled with 90Y and injected into mice in order to assess the in vivo inertness of the antibody-linked 90Y-ligand complexes. Levels of 90Y in femur shafts of the DOTA-B72.3 mice were low, being approximately 7 and 44%, respectively, of levels in the femur shafts of the caDTPA-B72.3 and CT-DTPA-B72.3 treated mice. This finding demonstrates the greater inertness and by implication the greater suitability for immunotherapy of the DOTA-90Y complex.
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Intraperitoneal infection with scrapie is established within minutes of injection and is non-specifically enhanced by a variety of different drugs. Arch Virol 1990; 112:103-14. [PMID: 2142415 DOI: 10.1007/bf01348988] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Single intraperitoneal (i.p.) doses of 16 different drugs were given to mice 2 h before injecting scrapie i.p. Scrapie was injected as serial ten-fold dilutions of standard inocula and the effective titres obtained were used as a measure of the relative efficiency of infection in treated compared to saline injected mice. Despite the wide variety of drugs tested, most of them increased, non-specifically, the efficiency of infection by 0.6 to 2.1 log10 i.p. LD50 units (i.e., 4 to 126-fold), but only when both drug and scrapie were given i.p. The effect was greatest with a 2 h or a 6 h interval suggesting an involvement either of resident peritoneal cells or of elicited cells such as polymorphonuclear neutrophils. There was no increase in the efficiency of infection after intervals of 2 or 7 days when induced macrophages would predominant. The reverse sequence of injections (scrapie-0.5 h-drug) had no effect despite the persistence of high scrapie titre in the peritoneum at the time of drug injection. However, the effect was restored by a second injection of scrapie in the sequence, scrapie-drug-scrapie. It is concluded that scrapie infection is established within minutes of injection but much of the inoculum is associated with peritoneal cells which are irrelevant to pathogenesis. Drugs may enhance the infection of relevant peritoneal cells or their targeting to the visceral lymphoreticular tissues where early replication takes place.
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The genomic identity of different strains of mouse scrapie is expressed in hamsters and preserved on reisolation in mice. J Gen Virol 1989; 70 ( Pt 8):2017-25. [PMID: 2504883 DOI: 10.1099/0022-1317-70-8-2017] [Citation(s) in RCA: 172] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
263K is the most widely used strain of agent in scrapie research because it produces very short incubation periods in golden hamsters and exceptionally high infectivity titres in clinically affected brain. 263K is also remarkable in having a very low pathogenicity for mice. Evidence is presented that 263K originated as a mutant that was strongly selected on passage in hamsters. Seven new passage lines have been established in hamsters using well characterized strains of mouse scrapie representing the 'drowsy goat' and SSBP/1 families of scrapie strains, and one natural scrapie source. Considerable differences between scrapie strains were found in hamsters using incubation period criteria alone. There was evidence that the parent strain of 263K might be 79V or a strain like it in the 'drowsy goat' family. Four of the hamster passage lines were established from scrapie strains that had been cloned in mice. Reisolates in mice were compared with original strains. By the criteria used, two of the reisolates were the same as the original strains. Two others were mutants with incubation periods longer than those of their parental strains but the mutants were different from one another. It is concluded that passage between mice and hamsters can select mutants that would otherwise be lost but there is also clear evidence that the genotypic identity of some scrapie strains is preserved on passage between different host species. These findings are important in the search for the putative nucleic acid genome of the scrapie agent.
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Lymphocyte sensitization to Aspergillus fumigatus in allergic bronchopulmonary aspergillosis. Clin Exp Immunol 1989; 76:34-40. [PMID: 2525438 PMCID: PMC1541741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Peripheral blood mononuclear cell (PBMC) proliferation induced by an extract of Aspergillus fumigatus (AF) was examined in patients with allergic bronchopulmonary aspergillosis (ABPA), all of whom had an immediate skin prick test reaction (SPT) and increased RAST binding to AF, and, for comparison, in individuals without immediate SPT reactivity or increased RAST binding to AF. The proliferative responses of PBMC from the ABPA patients were greater than those from the comparison donors. A substantial proportion of the comparison group, however, showed evidence of a specific immune response to AF, with AF-specific IgG measured by ELISA and specific lymphoproliferative responses. AF-responsive T cell lines and T cell clones were established from both ABPA patients and IgE-negative individuals. These clones, of helper/inducer (CD4+) phenotype, showed antigenic specificity and MHC restriction. The stimulating antigen was determined for four of six clones derived from a skin-prick-test-negative individual, and found to be of Mr 18 kD, possibly the major allergen, 'Ag 3'. ABPA patients showed a marked diminution of the proliferative response during disease exacerbation.
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Abstract
The pathogenesis of 139A scrapie has been studied in CW mice infected intraperitoneally (i.p.), intravenously (i.v.) or subcutaneously (s.c.). In mice splenectomised before i.p. infection, the evidence points to a neuroinvasive pathway from visceral lymph nodes (and other sites of scrapie replication in the peritoneum) to the thoracic spinal cord. However, in non-splenectomised mice, the major neuroinvasive pathway is clearly from spleen to thoracic cord because i.p. incubation periods are shorter and replication in the thoracic cord starts correspondingly earlier than in splenectomised mice. Studies of splenectomy at different times after i.p. infection show that pathogenesis becomes independent of the spleen once infection has initiated scrapie replication in the spinal cord. The simplest interpretation of all the evidence favours the spread of scrapie infection along splenic nerve fibres to the thoracic spinal cord. The same neuroinvasive pathway is suggested by the findings using the s.c. and i.v. routes of infection. In addition it was found that the 100-fold greater efficiency of infection by the i.v. compared to the i.p. route was entirely dependent on the spleen, because splenectomy before i.v. infection reduced its efficiency to the same as that found in i.p. infected (non-splenectomised) mice.
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Abstract
Infection via the gastrointestinal tract is likely to be a natural route of scrapie infection in sheep. This paper describes the pathogenesis of the 139A strain of scrapie introduced intragastrically (i.g.) into CW mice. There was an almost immediate uptake of infectivity and onset of replication in Peyer's patches which preceded replication in spleen. Splenectomy had no effect on incubation period suggesting that, in contrast to the intraperitoneal route, the spleen plays little or no role in the pathogenesis of 139A scrapie administered intragastrically. Replication in the CNS was first detectable in the thoracic spinal cord and later in brain. The evidence is consistent with neural spread of infection from the gastrointestinal tract, via the enteric and sympathetic nervous systems to spinal cord. Neuroinvasion may be initiated either via infection of Peyer's patches or directly by infection of nerve endings in the gut wall. The latter possibility means that pathogenesis may be completely independent of the lymphoreticular system.
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Characterization of immunologically important antigens and allergens of Aspergillus fumigatus. INTERNATIONAL ARCHIVES OF ALLERGY AND APPLIED IMMUNOLOGY 1989; 88:185-6. [PMID: 2651315 DOI: 10.1159/000234780] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Using a variety of immunochemical methods, including quantitative immuno-electrophoretic techniques, combined with gel filtration and iso-electric focusing, and production of monospecific antisera for identification and affinity purification, 4 major components of Aspergillus fumigatus have now been partially characterized. Numbering of these was derived from a reference allergic bronchopulmonary aspergillosis (ABPA) self-crossed radio-immuno-electrophoresis pattern of reactivity. Two major intracellular/cytoplasmic, concanavalin A (Con A)-binding antigens, Ag 7 and Ag 13, of molecular weights 150-200 and 70 kilodaltons (kD), respectively, were confirmed to be of importance for both ABPA and aspergilloma in specific sandwich enzyme-linked immunosorbent assays. A rapidly released component, Ag 5, of molecular weight 35 kD, proved both antigenic and allergenic, with aspergilloma patients having especially high-titre IgG antibodies. The major allergenic component Ag 3, of molecular weight 24 kD by gel filtration and 18 kD by SDS-PAGE was, like Ag 5, relatively heat-labile and non-Con-A-binding. Interestingly, T cell clones have been identified which respond primarily to an 18-kD fraction.
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Incubation periods in six models of intraperitoneally injected scrapie depend mainly on the dynamics of agent replication within the nervous system and not the lymphoreticular system. J Gen Virol 1988; 69 ( Pt 12):2953-60. [PMID: 3143808 DOI: 10.1099/0022-1317-69-12-2953] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The pathogenesis of intraperitoneally injected ME7 scrapie has been studied in two Sinc genotypes of mice which gave predictable but widely different incubation periods. Comparisons were made with three other mouse scrapie models and one model in hamsters (involving different strains of agent and an untyped isolate from sheep). Average incubation periods ranged from 114 days in the fastest model (263K/hamsters) to 482 days in the slowest (ME7/Sincp7 mice). There were only small differences between models in the times of onset of replication in spleen and cervical lymph nodes. We suggest that the lymphoreticular stage of pathogenesis initiates neuroinvasion in the peripheral nervous system within a few days to a few weeks of infection. Thereafter, pathogenesis appears to be dominated by neural events and replication in brain becomes detectable after approximately 54% of the remaining incubation period has elapsed, irrespective of its length. It is concluded that the differences between incubation periods of the six scrapie models depend mainly on the rate of a continuous process of replication and spread of infection in the peripheral and central nervous system, which is predetermined by scrapie strain and host genotype. The unpredictability of some other scrapie models (and the natural disease) could be explained by additional factors which restrict neuroinvasion from the lymphoreticular system.
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Temporary and permanent modifications to a single strain of mouse scrapie on transmission to rats and hamsters. J Gen Virol 1987; 68 ( Pt 7):1875-81. [PMID: 3110370 DOI: 10.1099/0022-1317-68-7-1875] [Citation(s) in RCA: 180] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The interspecies transmission of scrapie is frequently associated with exceptionally long incubation periods at first passage in the new host compared to later passages (the species barrier effect). The basis of this was investigated using the 139A strain of scrapie which had been cloned by three serial passages in mice at limiting infectious doses. Cloned scrapie was passaged through hamsters (twice) or rats (thrice) and then reisolated in mice. Large species barrier effects were encountered on mouse-to-hamster and hamster-to-mouse passage resulting in the isolation of a mutant strain, 139-H/M, with properties very different from 139A. In contrast, the strain reisolated from rats was indistinguishable from 139A. However, a large species barrier was encountered at the mouse-to-rat passage but not at the rat-to-mouse passage. It is suggested that the transmission of scrapie between species may be associated with no change in properties or a permanent change in the scrapie genome due to the selection of mutants. A third possibility, the donor species effect, is a temporary change occurring only at first passage in the new host species which is largely or entirely caused by the introduction of material from the previous host. We speculate that the donor species effect could be explained if some host protein forms a functional part of the infectious agent.
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Abstract
Previous studies of mice infected peripherally with 139A scrapie showed that scrapie agent initially replicates outside the CNS and that invasion of the CNS occurs several weeks later by neural spread of infection along visceral autonomic fibres to the mid-thoracic cord, and thence to brain. Direct intracerebral infection of brain bypasses the need for extraneural replication and gives shorter incubation periods than peripheral routes. However, it was also found that the duration of the scrapie replication phase in brain, before clinical disease develops, is actually shorter with peripheral routes than with the intracerebral route. We have now investigated this surprising observation using the intraspinal route to reproduce just the neural phase of scrapie pathogenesis seen after peripheral infection. In studies of three strains of scrapie (263K, 139A and ME7) in either hamsters or mice, we have fulfilled the prediction that incubation periods should be shorter after intraspinal infection than after intracerebral infection. Detailed studies of 139A scrapie showed that the shorter incubation period by the intraspinal route could be accounted for by the shorter duration of the scrapie replication phase in brain before clinical disease developed. As a consequence, the severity of the vacuolar lesions in brain at the clinical stage of all three scrapie models was less after intraspinal infection than after intracerebral infection but the severities of vacuolation after intraspinal and intraperitoneal infection were remarkably similar. We speculate that (a) the site of injection (or of invasion) of the central nervous system determines which neural pathways become accessible for the spread of scrapie infection, and that (b) the duration of the neural phase of scrapie pathogenesis is related to the complexity of the pathways between the site of invasion and the clinical target areas in which, it is suggested, scrapie must replicate for disease to develop.
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Salt intake and blood pressure in young adults from hypertensive and normotensive families. HUMAN NUTRITION. CLINICAL NUTRITION 1986; 40:333-42. [PMID: 3771286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Young adults with both parents in either the upper or lower quartile of blood pressure for their age groups were monitored for 13 d to assess whether there was a selective relationship between blood pressure and sodium excretion in the adults from the hypertensive but not from the normotensive families. Twelve 24-h urine measurements of sodium and potassium excretion were related to the mean of daily blood pressure measurements. Although a significant correlation between sodium excretion and blood pressure was found for the whole group, this related to the co-correlation of blood pressure and sodium excretion with the body weights of the subjects, no links being found in adults of either parental type once an allowance was made for body weight differences.
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Suppression of scrapie infection in mice by heteropolyanion 23, dextran sulfate, and some other polyanions. Antimicrob Agents Chemother 1986; 30:409-13. [PMID: 2430521 PMCID: PMC180570 DOI: 10.1128/aac.30.3.409] [Citation(s) in RCA: 110] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Studies of polyanions that suppress scrapie have been done to pinpoint the cell types in the lymphoreticular system which are important in pathogenesis and to suggest possible prophylactic or therapeutic strategies for the unconventional slow viruses. A regime of three daily injections of the inorganic heteropolyanion HPA-23 reduced the effective scrapie dose by more than 99%; i.e., some mice survived peripherally injected doses of 100 50% lethal dose units. The effect was greatest when the first dose of HPA-23 was given 4 h after injecting scrapie, but it declined rapidly as this interval was increased, and there was virtually no effect 2 days after infection. A single dose of high-molecular-weight organic polyanions such as carrageenan or dextran sulfate (DS-500) greatly reduced (i.e., greater than 99%) the efficiency of scrapie infection. In contrast to HPA-23, DS-500 was equally effective whether given 4 days before or 8 h after the time of infection. The antiscrapie effect of DS-500 appeared to be independent of its activity as a B-cell mitogen and of its ability to produce a cytotoxic blockade of phagocytic cells. DS-500 probably caused the aggregation and loss from blood of scrapie inoculum which was present immediately after injection, but it had additional effects on scrapie at later times.
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The effect of altered 5-hydroxytryptamine levels on beta-endorphin content in rat brain. PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE. SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE (NEW YORK, N.Y.) 1986; 182:187-93. [PMID: 3010328 DOI: 10.3181/00379727-182-42326] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The purpose of the present study was to examine the effect of altering the concentration of 5-hydroxytryptamine (5-HT) on beta-endorphin (beta-Ep) content in the hypothalamus, thalamus, and periaqueductal gray (PAG)-rostral pons regions of the rat brain. The selective 5-HT reuptake inhibitor, fluoxetine (10 mg/kg), significantly lowered beta-Ep content in the hypothalamus and the PAG. Parachlorophenylalanine, which inhibits 5-HT synthesis, significantly elevated beta-Ep in all brain parts studied. Intracisternal injections of the neurotoxin, 5',7'-dihydroxytryptamine, with desmethylimipramine pretreatment, significantly increased beta-Ep content in the hypothalamus and the PAG. In adrenalectomized rats, fluoxetine significantly decreased beta-Ep levels in the hypothalamus and increased the levels in the PAG. The results indicate that 5-HT may modulate the levels of brain beta-Ep.
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Abstract
Archaeopteryx lithographica might be regarded as the most important zoological species known, fossil or recent. Its importance lies not in that its transitional nature is unique-there are many such transitional forms at all taxonomic levels-but in the fact that it is an obvious and comprehensible example of organic evolution. There have been recent allegations that the feather impressions on Archaeopteryx are a forgery. In this report, proof of authenticity is provided by exactly matching hairline cracks and dendrites on the feathered areas of the opposing slabs, which show the absence of the artificial cement layer into which modern feathers could have been pressed by a forger.
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Abstract
Six out of 14 Bordetella bronchiseptica isolates from U.K. pigs each contained one plasmid, of 8.7-44 kb. All plasmid-containing isolates were sulfonamide resistant, and this property was shown to be plasmid-encoded. Five of the plasmids were related; two were indistinguishable from the broad-host-range plasmid, RSF1010. The other three, two of which appeared to be identical, were shown to have regions of homology with RSF1010. One of these regions encompassed the sulfonamide resistance determinant while the other contained oriV, which also determines plasmid incompatibility. None of the plasmids could be associated with virulence or phase variation, and it appears likely that they have been acquired in response to antibiotic pressure.
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Transmissible mink encephalopathy (TME) in Chinese hamsters: identification of two strains of TME and comparisons with scrapie. Neuropathol Appl Neurobiol 1986; 12:197-206. [PMID: 2940469 DOI: 10.1111/j.1365-2990.1986.tb00050.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
TME from a single source was transmitted by intracerebral injection to Chinese hamsters, producing clinical disease in all seven animals after incubation periods of over 600 days. The brain from each of the primary cases was used to establish separate intracerebral passage-lines of TME and this led to the isolation of two different strains of agent, designated 333K and 333W. These strains were easily distinguished by the incubation periods they produced (about 130 and 230 days, respectively) under standard conditions of infection, and by the characteristic profiles of vacuolation seen in different regions of the brain. Comparisons were made with a strain of scrapie passaged in Chinese hamsters, designated 34W, which could be distinguished from both strains of TME. Nevertheless the properties of the scrapie and TME strains overlapped, with one of the TME strains (333K) resembling the 34W strain of scrapie in Chinese hamsters more closely than the other TME strain (333W). These similarities strengthen the view that TME and scrapie are caused by a similar type of infectious agent. The very large 'species barrier effect' on transmitting TME to Chinese hamsters was in marked contrast to the minimal effect seen with scrapie and an explanation for this is suggested. Two interesting pathological features of the study were (a) the severe loss of pyramidal cells produced in the hippocampus by the 34W strain of scrapie, and (b) the focal, symmetrical vacuolation of the thalamus caused by 333K TME.
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Pathogenesis of scrapie (strain 263K) in hamsters infected intracerebrally, intraperitoneally or intraocularly. J Gen Virol 1986; 67 ( Pt 2):255-63. [PMID: 3080549 DOI: 10.1099/0022-1317-67-2-255] [Citation(s) in RCA: 145] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
After intracerebral (i.c.) infection of hamsters, the 263K strain of scrapie replicated at a nearly constant exponential rate until clinical disease developed when titres in brain averaged 9.8 log10 LD50 i.c. units/g. After intraperitoneal infection, scrapie replication was first detected in spleen, then in thoracic spinal cord and finally in lumbar cord and brain. This pattern suggests that invasion of the central nervous system occurs by spread of infection along certain visceral autonomic nerves. Infectivity was detected in the thoracic cord only 3 to 4 weeks after infection (incubation period 16 weeks) indicating the exceptional neuroinvasiveness of this scrapie model. This observation and the failure of splenectomy to lengthen incubation period raises the possibility of direct infection of nerve tissue in the peritoneum and transport to the thoracic cord with minimal prior replication of scrapie agent extraneurally. After intraocular infection of the right eye, replication (or accumulation) of scrapie was detected in the right optic nerve and left superior colliculus, then in the right superior colliculus and finally in the left optic nerve and medulla. This pattern shows that scrapie infection can spread along nerves, possibly by intra-axonal transport. The duration of agent replication in brain (between detectable onset of replication and clinical disease) was shortest after intraperitoneal infection (51 to 58 days), longer after intracerebral infection (81 to 88 days) and longest after intraocular infection (greater than 121 days). These differences may reflect the relative efficiency of the neural pathways by which infectivity spreads from different sites of entry in the brain to the postulated 'clinical target areas'.
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Abstract
Eighty-five subjects were tested for the presence of circulating candidal antigen (CAg) and anti-candidal antibody (CAb) using both an enzyme immunoassay (ELISA) and counterimmunoelectrophoresis (CIE). The 72 studied controls included laboratory volunteers; hospitalized patients without evidence of infection; febrile hospitalized patients without evidence of candidiasis; and patients with superficial candidiasis and candiduria. The control subjects were compared with 13 patients with proven disseminated candidal infection (disease prevalence = 15%). The ELISA CAb test was of greater individual sensitivity (92%) in separating patients with systemic candidiasis from all controls combined than the ELISA CAg, CIE CAg, or CIE CAb test (61%, 15%, 69%, respectively). The CIE CAg test, though specific (100%), was insensitive. Sensitivity, specificity, and predictive values were generally enhanced by employing combinations of tests. Sera from patients with disseminated candidiasis were much more likely to yield a positive result by two or more serologic tests than were control sera (p = less than 0.0004). The sensitivity of combinations ranged from 15% to 92%. The specificity of combinations ranged from 21% to 100%. The predictive value positive of combinations test ranged from 40% to 100%. Predictive value negative of combinations ranged from 69% to 98%. Patients with a variety of superficial and deep candidal infections apparently have detectable circulating CAb and/or CAg. The ELISA CAb test was superior to the other tests in identifying patients with disseminated candidiasis. Combinations of serologic tests may be superior to individual tests in the diagnosis or exclusion of serious disease due to Candida albicans.
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Abstract
A comprehensive study has been made of metabolites, enzymes and receptors for a variety of neurotransmitter systems in different parts of the CNS from mice affected with 139A scrapie. Studies were made at the early clinical stage so as to minimise secondary alterations in terminally sick mice. Even though histological lesions (vacuolation) are widespread in the CNS in this model of scrapie, no consistent neurochemical changes were found in mid- or anterior brain. In the cerebellum, the activity of glutamic acid decarboxylase was reduced and the binding of [3H]muscimol to gamma-aminobutyric acid receptors was increased. In the brain stem, the concentration of 5-hydroxyindoleacetic acid (5-HIAA) was increased and there was a reduced binding of appropriate ligands to serotonin and to muscarinic cholinergic receptors. In the spinal cord, the activity of choline acetyl transferase was reduced and the concentration of 5-HIAA was increased. The extent of these alterations was about 20-40% of control values. The specificity of these changes for a few neurotransmitter systems in hind brain and spinal cord raised the possibility of their being a primary cause of clinical disease and led us to study a different scrapie model. Present and published findings show that an increased concentration of 5-HIAA, some alterations in the binding properties of serotonin receptors and a decreased number of muscarinic receptor sites are common to both 139A scrapie in CW mice and 263K scrapie in hamsters.
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Competition between strains of scrapie depends on the blocking agent being infectious. Intervirology 1985; 23:74-81. [PMID: 3920169 DOI: 10.1159/000149588] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Compton White mice (Sincs7) were injected twice intraperitoneally, first with the 22A strain of scrapie agent (in brain homogenates) and then, after 105 days, with the 22C strain. Incubation periods were calculated from the time of the first injection. The experiment was designed so that, with no interaction between strains, the second strain (22C) should have produced cases about 300-350 days after the first injection, depending on the dose of 22C. This was well before the limit of 470 days set by the mean incubation period minus 3 SD of 22A alone: a limit which was used to distinguish 22C from 22A clinical cases. In fact, 22A blocked 22C as shown by (i) the lengthening of 22C incubation periods, (ii) the reduced proportion of cases due to 22C, and (iii) the reduced effective titer of 22C. The blocking efficiency of 22A was not greatly reduced by physicochemical treatments that had little or no effect on its infectivity by the intraperitoneal route. However, treatment of 22A homogenates with 6 M urea virtually eliminated infectivity and also abolished blocking ability. It is concluded that competition depends on the infectivity of the scrapie strain used for blocking.
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Pathogenesis of mouse scrapie. Evidence for direct neural spread of infection to the CNS after injection of sciatic nerve. J Neurol Sci 1983; 61:315-25. [PMID: 6418861 DOI: 10.1016/0022-510x(83)90165-x] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Previous studies of peripherally injected mouse scrapie suggested that invasion of the CNS occurs initially in mid-thoracic cord by neural spread of infection from spleen and other visceral sites of extraneural replication. We now show that infection of the left sciatic nerve leads to direct spread of infection to brain (at a rate of approximately 1.0-2.0 mm/day), bypassing the need for extraneural replication and thus producing shorter incubation periods. However, the efficiency of intraneural infection is low. It can be increased by crush injury or by the injection of lysophosphatidyl choline, both of which temporarily increase the surface area of axolemma exposed to inoculum. Once infection is established, agent seems to spread throughout the nervous system but, at the clinical stage of disease, the titres in the PNS are much lower than in the CNS.
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Disinfection studies with two strains of mouse-passaged scrapie agent. Guidelines for Creutzfeldt-Jakob and related agents. J Neurol Sci 1983; 59:355-69. [PMID: 6308174 DOI: 10.1016/0022-510x(83)90021-7] [Citation(s) in RCA: 100] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A variety of disinfection procedures were tested on two strains of scrapie agent, treated either as brain macerates (autoclaving) or as 10% homogenates (chemical treatments). It is suggested that a given treatment should produce a titre loss, of both strains of scrapie, of at least 10(4) units before it be regarded as useful for the disinfection of the agents of scrapie and Creutzfeldt-Jakob disease (CJD). By this criterion, treatment at room temperature with about 4% Hycolin (0.6% chlorinated phenols), 0.2% permanganate, 5% Tego (dodecyl-di(aminoethyl)-glycine) or 5% sodium dodecyl sulphate (SDS) are unsuitable. However, data indicate that SDS might be used to reduce the heat stability of scrapie agent. Hypochlorite (Sterilex) was the only satisfactory chemical reagent tested. At least 10(4)-10(5) units of infectivity were lost by treatment with hypochlorite containing 1,000 ppm available chlorine after a 4-16 h exposure, or containing 10,000 ppm available chlorine after a half-hour exposure. The latter result points to the use of concentrated hypochlorite (about 2% available chlorine; approximately 20% Sterilex) to decontaminate surfaces. We suggest that the cleaning action of SDS, or other strong detergents, might also help to decontaminate surfaces, but studies on this are needed. Autoclaving at 126 degrees C for 1-2 h reduced titres by 10(3)-10(7) units, depending on the strain of agent. However, total disinfection of brain containing high titres of infectivity was approached only at 136 degrees C when titre losses of about 10(6) units were obtained by autoclaving for 4-32 min. Further studies are needed before we can make simple, general recommendations for the disinfection of CJD agents in hospital practice.
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