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Dold PL, Jones RM, Bye CM. Importance and measurement of decay rate when assessing nitrification kinetics. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2005; 52:469-77. [PMID: 16459823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Nitrification kinetics are important for process design, optimization and capacity rating of activated sludge wastewater treatment plants. Assessment of nitrification behaviour historically has focused on measuring the nitrifier maximum specific growth rate, micro(AUT). Very little attention has been directed at the of nitrifier organism rate has been assumed negligible. However, incorrect assessment of decay rate leads to errors in the micro(AUT) estimate; the magnitude of the error depends on the micro(AUT) measurement method employed. This paper illustrates why decay rate is important when measuring micro(AUT), and that the decay rate is significant. The paper also explains why measurement methods for nitrifier decay may have underestimated the decay rate. Results from an experiment incorporating improvements to previously suggested methods and data analysis are presented.
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Jones RM, Bye CM, Dold PL. Nitrification parameter measurement for plant design: experience and experimental issues with new methods. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2005; 52:461-8. [PMID: 16459822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Nitrification kinetics are important for process design, optimization, and capacity rating of activated sludge wastewater treatment plants. A Water Environment Research Foundation (WERF) project on Methods for Wastewater Characterization in Activated Sludge Modeling (WERF, 2003) focused significantly on the development of procedures for measuring the nitrifier maximum specific growth rate, micro(AUT). In addition, the importance of (and lack of data for) the nitrifier decay rate, b(AUT), was identified. This paper describes three bench-scale methods for measuring micro(AUT): the Low F/M SBR, Washout and High F/M methods. During the WERF project, the importance of pH and temperature control was investigated briefly; this paper summarizes further experimental work performed to address these issues. A summary of micro(AUT) measurements in a number of locations and using the different measurement techniques is provided.
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Jones RM, Jones PL, Gildersleve CD, Hall JE, Harding LJE, Chawathe MS. The Cardiff paediatric laryngoscope blade: a comparison with the Miller size 1 and Macintosh size 2 laryngoscope blades. Anaesthesia 2004; 59:1016-9. [PMID: 15488063 DOI: 10.1111/j.1365-2044.2004.03839.x] [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] [Indexed: 11/30/2022]
Abstract
The Cardiff paediatric laryngoscope blade is a single blade that has been designed for use in children from birth to adolescence. This open, randomised, crossover study compared the Cardiff blade with the straight, size 1, Miller laryngoscope blade in 39 infants under 1 years of age and the curved, size 2, Macintosh blade in 39 children aged 1-16 years. The same laryngoscopic view was obtained with the Cardiff and Miller blades in 26 patients; the view was better with the Cardiff blade in seven patients and better with the Miller blade in six (median (IQR [range]) grade of laryngoscopy 1 (1-2 [1-3]) vs. 1 (1-2 [1-3]), respectively; p = 0.405). The Cardiff blade was faster at gaining a view than the Miller blade (mean (SD) time 8.5 (2.9) s vs. 10.2 (3.5) s, respectively; 95% CI for difference -2.8 to -0.4; p = 0.009). The Cardiff and Macintosh blades produced the same view in 32 patients; the view was better with the Cardiff blade in seven patients (median (IQR [range]) grade of laryngoscopy 1 (1-1 [1-3]) vs. 1 (1-2 [1-3]), respectively; p = 0.008). There was no difference in time to gain these views: mean (SD) 8.7 (3.0) s vs. 9.3 (2.7) s, respectively (95% CI for difference -1.58 to 0.40; p = 0.237). The Cardiff paediatric laryngoscope blade compares favourably with these two established laryngoscope blades in children.
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104
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Turner SI, Jones RM. Complete situs inversus in a horse. Vet Rec 2004; 155:96. [PMID: 15311812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
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105
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Jones RM, Baldwin MJ. Development of a Theoretical Model of Nickel(II) Tris(oxime)amine Dichloride with Comparison to X-ray Crystallography and Vibrational Spectroscopy. J Phys Chem A 2004. [DOI: 10.1021/jp037139r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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106
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Hosey MT, Makin A, Jones RM, Gilchrist F, Carruthers M. Propofol intravenous conscious sedation for anxious children in a specialist paediatric dentistry unit. Int J Paediatr Dent 2004; 14:2-8. [PMID: 14706022 DOI: 10.1111/j.1365-263x.2004.00521.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To report on both the use and dosage of propofol, as a new intravenous (IV) conscious sedative agent, for anxious children referred to a specialist paediatric dentistry service. SETTING Paediatric Dentistry Unit, Glasgow Dental Hospital and School. SAMPLE Thirty-four children, 25 females and 9 males, mean age 12 years 10 months, with a mean weight of 54.6 kg (range 30-110 kg). METHODS Report from 34 patients receiving intravenous sedation for the first time in respect of weight dose and amount of treatment completed. RESULTS Thirty-two children successfully accepted operative dental care on their first visit, they received a mean total dose of 146.25 mg of propofol (range 10 mg to 356 mg); in relation to body weight, the mean was 2.5 mg/kg (range 0.2-5.4 mg/kg). The treatment that they received included fissure sealants, amalgam and adhesive restorations, root canal therapy and single and multiple extractions. Their sedation and recovery were uneventful. CONCLUSIONS Sub-anaesthetic doses of propofol used for IV conscious sedation infusion facilitated operative dental treatment in anxious children.
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Chawathe MS, Jones RM, Gildersleve CD, Harrison SK, Morris SJ, Eickmann C. Detection of epidural catheters with ultrasound in children. Paediatr Anaesth 2003; 13:681-4. [PMID: 14535905 DOI: 10.1046/j.1460-9592.2003.01151.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The aim of this study was to assess whether a noninvasive imaging technique such as ultrasound could visualize an epidural catheter in the epidural space in children. METHODS Following local ethics committee approval and informed parental consent a pilot study of 12 cases was performed. Children undergoing major surgery requiring epidural analgesia were recruited. All catheters were introduced via the lumbar region. All children were scanned within 24 h of epidural insertion by consultant paediatric radiologists. If the catheter was identified in the epidural space then an attempt was made to visualize the entire length of the catheter. RESULTS The epidural catheter was detected in nine of 12 patients. All of these were less than 6 months old. The entire length of the catheter was visualized in five of the nine patients. It was possible to estimate the most cephalad level of the catheter in seven of the nine patients. This was in the thoracic region in all cases and an appropriate level for the intended surgical procedure. It was not possible to precisely identify the tip of the catheter as a distinct entity using ultrasound. CONCLUSION This study shows that it is possible to visualize an epidural catheter in the epidural space in children under 6 months of age using ultrasound.
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Abstract
We describe four examples of the XO condition in wild mammals. One XO house mouse (Mus musculus domesticus) was caught in nature and subsequently gave birth to three litters in captivity, confirming for wild mice the fertility observed for XO laboratory mice. Two other XO house mice were produced from laboratory crosses of wild-caught mice. An immature XO common shrew (Sorex araneus) was caught in nature; this appears to be the first XO recorded in the order Insectivora. We collected data from researchers studying chromosome variation in house mice and common shrews and found an overall incidence of 0.22% sex chromosome aneuploidy in 4608 mice and 0.05% in 6625 shrews. The discrepancy related to a much higher frequency of XO's in mice than shrews. Single XXY and XYY shrews and an XXX mouse have been recorded in nature.
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Negus SS, Mello NK, Linsenmayer DC, Jones RM, Portoghese PS. Kappa opioid antagonist effects of the novel kappa antagonist 5'-guanidinonaltrindole (GNTI) in an assay of schedule-controlled behavior in rhesus monkeys. Psychopharmacology (Berl) 2002; 163:412-9. [PMID: 12373442 DOI: 10.1007/s00213-002-1038-x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2001] [Accepted: 01/16/2002] [Indexed: 10/27/2022]
Abstract
RATIONALE Opioid receptors are divided into three types: kappa, mu, and delta receptors. Receptor-selective antagonists are useful experimental tools for evaluation of opioid receptor-mediated processes. 5'-Guanidinonaltrindole (GNTI) was recently developed as a novel kappa-selective antagonist. OBJECTIVES To evaluate the potency, time course, and selectivity of GNTI's opioid antagonist effects in rhesus monkeys in an assay of schedule-controlled responding. METHODS Five rhesus monkeys were trained to respond under a fixed ratio 30 schedule of food reinforcement. The rate-decreasing effects of the kappa agonists U50,488 and U69,593, the mu agonist morphine, and the delta agonist SNC80 were examined alone and after pretreatment with GNTI (0.1 and 1.0 mg/kg i.m.; 1 h to 14 days). RESULTS U50,488, U69,593, morphine, and SNC80 dose-dependently decreased response rates in this procedure. GNTI produced a dose- and time-dependent antagonism of the rate-decreasing effects of U50,488. The kappa antagonist effects of GNTI had a slow onset and a long duration of action, and peak antagonist effects were observed after 24 h. A higher dose of 3.2 mg/kg GNTI eliminated responding in one monkey and was not studied further. The antagonist effects of GNTI were kappa selective, because 1.0 mg/kg GNTI also antagonized the effects of U69,593, but not those of morphine or SNC80. CONCLUSIONS These results suggest that GNTI is a potent and selective kappa antagonist with a slow onset and long duration of action in rhesus monkeys. Relative to the prototype kappa antagonist nor-binaltorphimine, GNTI may have some advantages as a tool for the study of kappa receptor-mediated processes.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- Analgesics/pharmacology
- Analgesics, Non-Narcotic/pharmacology
- Animals
- Benzamides/pharmacology
- Benzeneacetamides
- Conditioning, Operant/drug effects
- Dose-Response Relationship, Drug
- Drug Interactions
- Female
- Guanidines
- Macaca mulatta
- Male
- Morphinans
- Morphine/pharmacology
- Naltrexone/analogs & derivatives
- Naltrexone/pharmacology
- Narcotic Antagonists/pharmacology
- Narcotics/pharmacology
- Piperazines/pharmacology
- Pyrrolidines/pharmacology
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Reinforcement Schedule
- Time Factors
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Torbert HA, Daniel TC, Lemunyon JL, Jones RM. Relationship of soil test phosphorus and sampling depth to runoff phosphorus in calcareous and noncalcareous soils. JOURNAL OF ENVIRONMENTAL QUALITY 2002; 31:1380-1387. [PMID: 12175059 DOI: 10.2134/jeq2002.1380] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A study was initiated to investigate the relationship between soil test P and depth of soil sampling with runoff losses of dissolved molybdate reactive phosphorus (DMRP). Rainfall simulations were conducted on two noncalcareous soils, a Windthorst sandy loam (fine, mixed, thermic Udic Paleustalf) and a Blanket clay loam (fine, mixed, thermic Pachic Argiustoll), and two calcareous soils, a Purves clay (clayey, smectitic, thermic Lithic Calciustoll) and a Houston Black clay (fine, smectitic, thermic Udic Haplustert). Soil (0- to 2.5-, 0- to 5-, and 0- to 15-cm depths) and runoff samples were collected from each of the four soils in permanent pasture exhibiting a wide range in soil test P levels (as determined by Mehlich III and distilled water extraction) due to prior manure applications. Simulated rain was used to produce runoff, which was collected for 30 min. Good regression equations were derived relating soil test P level to runoff DMRP for all four soil types, as indicated by relatively high r2 values (0.715 to 0.961, 0- to 5-cm depth). Differences were observed for the depth of sampling, with the most consistent results observed with the 0- to 5-cm sampling depth. Runoff DMRP losses as a function of the concentration of P in soil were lower in calcareous soils (maximum of 0.74 mg L(-1)) compared with noncalcareous soils (maximum of 1.73 mg L(-1)). The results indicate that a soil test for environmental P could be developed, but it would require establishing different soil test P level criteria for different soils or classes of soils.
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Bondarets N, Jones RM, McDonald F. Analysis of facial growth in subjects with syndromic ectodermal dysplasia: a longitudinal analysis. Orthod Craniofac Res 2002; 5:71-84. [PMID: 12086328 DOI: 10.1034/j.1600-0544.2002.01159.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To examine the craniofacial growth pattern of patients diagnosed with syndromic ectodermal dysplasia. DESIGN Mixed longitudinal analysis of lateral cephalograms. SETTING The data were analysed using a multilevel modelling technique with the MLwiN application software and the results presented numerically and graphically. SAMPLE POPULATION All 61 subjects had severe hypodontia with the number of absent teeth (excluding third molars) ranging from 6 to 28 (mean = 15.4). At presentation the subjects had a mean age of 133 months and were followed longitudinally for between one and five subsequent occasions (mean 2.66 occasions; mean age at completion of observation 207 months). OUTCOME MEASURES Lateral cephalograms taken at each visit. EXPERIMENTAL VARIABLES Analysis of four angular measurements and four linear measurements, together with one calculated ratio. RESULTS Growth curves are presented showing the trends of craniofacial growth. CONCLUSIONS The most significant findings were for a universal tendency for the individuals to undergo a change in sagittal relationship of the jaws, becoming markedly more Class III with time. We have also demonstrated a significant difference in growth between the anterior and posterior face heights indicating that the subjects have a tendency to an anterior growth rotation.
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Jones RM, Lu L, Helgeson R, Bergstedt TS, McBranch DW, Whitten DG. Building highly sensitive dye assemblies for biosensing from molecular building blocks. Proc Natl Acad Sci U S A 2001; 98:14769-72. [PMID: 11742082 PMCID: PMC64933 DOI: 10.1073/pnas.251555298] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Fluorescence superquenching is investigated for polyelectrolytes consisting of cyanine dye pendant polylysines ranging in number of polymer repeat units (N(PRU)) from 1 to 900, both in solution and after adsorption onto silica nanoparticles. As N(PRU) increases, the absorption and fluorescence evolve from monomer spectra to red-shifted features indicative of molecular J aggregates. In solution, the superquenching sensitivity toward an anionic electron acceptor increases by more than a millionfold over the N(PRU) range from 1 to 900. The dramatic increase is attributed to enhanced equilibrium constants for binding the quenchers, and the amplified quenching of a delocalized exciton of approximately 100 polymer repeat units. The self-assembly of monomer onto silica and clay nanoparticles leads to formation of J aggregates, and surface-activated superquenching enhanced 10,000x over the monomer in solution, indicating the formation of "self-assembled polymers" on the nanoparticle surface. Utilization of these self-assembled polymers as high-sensitivity biosensors is demonstrated.
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Blake DA, Jones RM, Blake RC, Pavlov AR, Darwish IA, Yu H. Antibody-based sensors for heavy metal ions. Biosens Bioelectron 2001; 16:799-809. [PMID: 11679258 DOI: 10.1016/s0956-5663(01)00223-8] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Competitive immunoassays for Cd(II), Co(II), Pb(II) and U(VI) were developed using identical reagents in two different assay formats, a competitive microwell format and an immunosensor format with the KinExA 3000. Four different monoclonal antibodies specific for complexes of EDTA-Cd(II), DTPA-Co(II), 2,9-dicarboxyl-1,10-phenanthroline-U(VI), or cyclohexyl-DTPA-Pb(II) were incubated with the appropriate soluble metal-chelate complex. In the microwell assay format, the immobilized version of the metal-chelate complex was present simultaneously in the assay mixture. In the KinExA format, the antibody was allowed to pre-equilibrate with the soluble metal-chelate complex, then the incubation mixture was rapidly passed through a microcolumn containing the immobilized metal-chelate complex. In all four assays, the KinExA format yielded an assay with 10-1000-fold greater sensitivity. The enhanced sensitivity of the KinExA format is most likely due to the differences in the affinity of the monoclonal antibodies for the soluble versus the immobilized metal-chelate complex. The KinExA 3000 instrument and the Cd(II)-specific antibody were used to construct a prototype assay that could correctly assess the concentration of cadmium spiked into a groundwater sample. Mean analytical recovery of added Cd(II) was 114.25+/-11.37%. The precision of the assay was satisfactory; coefficients of variation were 0.81-7.77% and 3.62-14.16% for within run and between run precision, respectively.
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Abstract
Cone snails have long been of note due to their colorful shells and deadly venom. Over the years, a number of people who have encountered these molluscs have been injured or killed by their sting. Biochemical analysis of the venom components has revealed a plethora of peptides and proteins that target a variety of receptors and ion channels. Pharmaceutical companies are now utilizing the selectivity and potency of Conus-derived peptides to develop novel medications for pain, epilepsy and other disorders.
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Fleming WR, Elliott TB, Jones RM, Hardy KJ. Randomized clinical trial comparing totally extraperitoneal inguinal hernia repair with the Shouldice technique. Br J Surg 2001; 88:1183-8. [PMID: 11531864 DOI: 10.1046/j.0007-1323.2001.01865.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The optimal technique for inguinal hernia repair remains contentious. This study compared the Shouldice repair with the totally extraperitoneal endoscopic (TEP) method in a randomized clinical trial, with quality of life (QoL) and cost analysis. METHODS Two hundred patients were randomized to Shouldice or TEP repair. Patients were assessed after operation by questionnaire to determine operative outcomes, complications, QoL, and return to work and normal lifestyle. RESULTS There were 117 TEP and 115 Shouldice repairs. Median operating time was longer for TEP repair (70 versus 56 min; P = 0.0001), but patients were discharged earlier (68 versus 48 per cent within 1 day; P = 0.0065), and had a quicker return to work (14 versus 30 days; P = 0.0001) and normal lifestyle (21 versus 35 days; P = 0.0001). Open repair was nearly 40 per cent cheaper. Late follow-up in 171 patients (86 per cent) at a median of 1.3 years found that TEP repair led to fewer complications at 1 year (9 versus 21 per cent; P = 0.05) and was associated with significant improvement for the QoL components of work performance and satisfaction, physical symptoms and sense of well-being. CONCLUSION TEP repair results in fewer complications and an earlier return to work and normal lifestyle, but is more expensive and takes longer to perform.
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117
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Jewett DC, Grace MK, Jones RM, Billington CJ, Portoghese PS, Levine AS. The kappa-opioid antagonist GNTI reduces U50,488-, DAMGO-, and deprivation-induced feeding, but not butorphanol- and neuropeptide Y-induced feeding in rats. Brain Res 2001; 909:75-80. [PMID: 11478923 DOI: 10.1016/s0006-8993(01)02624-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Antagonists selective for either kappa- [e.g. nor-binaltorphimine (nor-BNI)] and mu- (e.g. beta-funaltrexamine) opioid receptors have previously been shown to reduce both kappa- and mu-opioid-induced feeding. In the present studies, the anorectic effects of GNTI, a newly synthesized antagonist selective for kappa-opioid receptors, were studied in rats. GNTI (0.032-0.32 nmol; i.c.v.), administered 15 min prior to food access, reduced feeding induced by the kappa-opioid agonist U50,488 (producing a 70% maximal decrease), the mu-opioid agonist DAMGO (90% maximal decrease), and 24 h acute food deprivation (60% maximal decrease). GNTI did not reduce the orexigenic effects of butorphanol, an agonist that binds to both kappa- and mu-opioid receptors, and neuropeptide Y (NPY). Taken together, these results suggest that GNTI is a potent anorectic agent and opioid antagonist in rats. Like nor-BNI, GNTI reduced feeding induced by both kappa- and mu-opioid agonists. However, unlike nor-BNI, GNTI did not alter the orexigenic effects of butorphanol or NPY. Given the selectivity of GNTI and its effectiveness in several of the present experiments, its potency, and its short duration of action compared to nor-BNI, GNTI may serve to be a useful tool to study behavioral effects mediated by kappa-opioid receptors.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- Analgesics, Non-Narcotic/pharmacology
- Analgesics, Opioid/pharmacology
- Animals
- Brain/drug effects
- Brain/metabolism
- Butorphanol/pharmacology
- Drug Interactions/physiology
- Eating/drug effects
- Eating/physiology
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/pharmacology
- Food Deprivation/physiology
- Guanidines
- Male
- Morphinans
- Naltrexone/analogs & derivatives
- Naltrexone/pharmacology
- Narcotic Antagonists/pharmacology
- Narcotics/pharmacology
- Neuropeptide Y/metabolism
- Neuropeptide Y/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/metabolism
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Jones RM, Bergstedt TS, McBranch DW, Whitten DG. Tuning of superquenching in layered and mixed fluorescent polyelectrolytes. J Am Chem Soc 2001; 123:6726-7. [PMID: 11439073 DOI: 10.1021/ja0157797] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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119
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Sharma SK, Jones RM, Metzger TG, Ferguson DM, Portoghese PS. Transformation of a kappa-opioid receptor antagonist to a kappa-agonist by transfer of a guanidinium group from the 5'- to 6'-position of naltrindole. J Med Chem 2001; 44:2073-9. [PMID: 11405645 DOI: 10.1021/jm010095v] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The importance of the indole scaffold of GNTI 3 in directing its address (5'-guanidinium group) to associate with the Glu297 residue of the kappa-opioid receptor was investigated by the synthesis and biological evaluation of its 4'- (4a), 6'- (4b), and 7'- (4c) regioisomers. The finding that only the 5'-regioisomer (GNTI) possessed potent kappa-opioid antagonist activity and high affinity at kappa-receptors illustrates the importance of the 5'-position in orienting the guanidinium group to the proper recognition locus (Glu 297) for potent kappa-antagonist activity. The discovery that the 6'-regioisomer of GNTI was a potent kappa-agonist, together with the results of site-directed mutagenesis studies that are consistent with association between the 6'-guanidinium group and Glu297, suggest that the transition from an inactive to an active state of the kappa-receptor involves a conformational change of TM6. We propose that association of the 6'-guanidinium group of 4b with Glu297 promotes axial rotational motion of transmembrane helix VI which leads to receptor activation via a conformational change of inner loop 3.
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MESH Headings
- Animals
- Cell Line
- Cloning, Molecular
- Guanidine/chemistry
- Guinea Pigs
- Humans
- In Vitro Techniques
- Molecular Conformation
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/metabolism
- Mutagenesis, Site-Directed
- Naltrexone/analogs & derivatives
- Naltrexone/chemistry
- Naltrexone/metabolism
- Naltrexone/pharmacology
- Narcotic Antagonists/chemistry
- Narcotic Antagonists/metabolism
- Narcotic Antagonists/pharmacology
- Rats
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/metabolism
- Structure-Activity Relationship
- Transfection
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Jones RM, Hardy KJ. The hepatic artery: a reminder of surgical anatomy. JOURNAL OF THE ROYAL COLLEGE OF SURGEONS OF EDINBURGH 2001; 46:168-70. [PMID: 11478014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
This study was carried out to document the anatomy of the hepatic artery with the purpose of reminding surgeons of the need for this essential knowledge in order to practice safe hepatobiliary surgery. Repeated surgical mistakes on patients referred to our unit prompted the study. One hundred and eighty consecutive livers procured for transplantation was studied, and the anatomy drawn immediately after dissection. The left hepatic artery arose from the left gastric artery in 15%, and either the splenic, gastroduodenal artery or the aorta in 4% of cases. The right hepatic artery arose from the superior mesenteric artery in 15%, the gastroduodenal, right gastric artery or aorta in 10% of cases. There was a major variation of the coeliac axis in 9% of cases studied. Overall, there was an abnormality in 43% of dissections: 48% were multiple and 27% had more than two vascular variations. A constant pattern of abnormalities occurred in the anatomy of the hepatic artery. Realisation of this vascular pattern should make identification of the anatomy easier. When there is one vascular variation, there is a high chance of there being multiple variations.
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121
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Jones RM, Van De Water RW, Lindsey CC, Hoarau C, Ung T, Pettus TR. A Mild Anionic Method for Generating o-Quinone Methides: Facile Preparations of Ortho-Functionalized Phenols. J Org Chem 2001; 66:3435-41. [PMID: 11348127 DOI: 10.1021/jo001752e] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A low-temperature method for generating o-quinone methides is described which permits facile introduction of assorted R substituents onto the aryl ring system at low temperature. The method is useful for the efficient preparation of ortho-ring-alkylated phenols.
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Collins AJ, Husni M, Jones RM. A versatile high-magnification Kerr magneto-optic microscope. ACTA ACUST UNITED AC 2001. [DOI: 10.1088/0022-3735/11/6/014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
Dexmedetomidine-propofol pharmacodynamic interaction was evaluated in nine healthy subjects in a crossover design. Dexmedetomidine/placebo was infused using a computer-controlled infusion pump (CCIP) to maintain a pseudo-steady-state plasma concentration of 0.66 +/- 0.080 or 0 ng/mL, respectively. Forty-five minutes after the dexmedetomidine/placebo infusion was started, propofol was infused using a second CCIP to achieve a stepwise logarithmically ascending propofol concentration (1.00 to 13.8 microg/mL) profile. Each propofol step lasted 10 min. Blood was sampled for plasma concentration determination, and pharmacodynamic endpoint assessments were made during the study. Propofol and dexmedetomidine/placebo infusions were terminated when three endpoints (subjects were too sedated to hold a syringe, followed by loss of eyelash reflex, followed by loss of motor response to electrical stimulation) were achieved sequentially. The concentration of propofol associated with 50% probability of achieving a pharmacodynamic endpoint in the absence of dexmedetomidine (EC50; placebo treatment) was 6.63 microg/mL for motor response to electrical stimulation and ranged from 1.14 to 1.98 microg/mL for the ability to hold a syringe, eyelash reflex, and sedation scores. The apparent EC50 values of propofol (EC50APP; concentration of propofol at which the probability of achieving a pharmacodynamic endpoint is 50% in the presence of dexmedetomidine concentrations observed in the current study; dexmedetomidine treatment) were 0.273, 0.544-0.643, and 3.89 microg/mL for the ability to hold a syringe, sedation scores, and motor response, respectively. Dexmedetomidine reduced propofol concentrations required for sedation and suppression of motor response. Therefore, the propofol dose required for sedation and induction of anesthesia may have to be reduced in the presence of dexmedetomidine.
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Sanderson MA, Jones RM, McFarland MJ, Stroup J, Reed RL, Muir JP. Nutrient movement and removal in a switchgrass biomass-filter strip system treated with dairy manure. JOURNAL OF ENVIRONMENTAL QUALITY 2001; 30:210-216. [PMID: 11215655 DOI: 10.2134/jeq2001.301210x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Manure use on cropland has raised concern about nutrient contamination of surface and ground waters. Warm-season perennial grasses may be useful in filter strips to trap manure nutrients and as biomass feedstock for nutrient removal. We explored the use of 'Alamo' switchgrass (Panicum virgatum L.) in a biomass production-filter strip system treated with dairy manure. We measured changes in extractable P in the soil, NO3 -N in soil water, and changes in total reactive P and chemical oxygen demand (COD) of runoff water before and after a switchgrass filter strip. Five rates of dairy manure (target rates of 0, 50, 100, 150, and 200 kg N ha(-1) from solid manure in 1995; 0, 75, 150, 300, and 600 kg N ha(-1) from lagoon effluent in 1996 and 1997) were surface-applied to field plots of switchgrass (5.2 by 16.4 m) with a 5.2- by 16.4-m switchgrass filter strip below the manured area. Yield of switchgrass from the manured area increased linearly with increasing manure rate in each year. Soil water samples collected at 46 or 91 cm below the soil surface on 30 dates indicated < 3 mg L(-1) of NO3-N in all plots. Concentrations of total reactive P in surface runoff water were reduced an average of 47% for the 150 kg N rate and 76% for the 600 kg N rate in 1996 and 1997 after passing through the strip. Manure could effectively substitute for inorganic fertilizer in switchgrass biomass production with dual use of the switchgrass as a vegetative filter strip.
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Jones RM, Williams PA. areCBA is an operon in Acinetobacter sp. strain ADP1 and Is controlled by AreR, a sigma(54)-dependent regulator. J Bacteriol 2001; 183:405-9. [PMID: 11114944 PMCID: PMC94893 DOI: 10.1128/jb.183.1.405-409.2001] [Citation(s) in RCA: 8] [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
The areCBA genes in Acinetobacter sp. strain ADP1, determining growth on benzyl alkanoates, are shown to be transcribed as a single operon and regulated by areR, which encodes a regulatory protein of the NtrC/XylR family. Assays of the Are enzymes and of two insertions of lacZ as a reporter gene have shown that the operon is induced by benzyl acetate, benzyl alcohol, and benzaldehyde, as well as 2- and 4-hydroxybenzyl acetates and benzyl propionate and butyrate. Two adjacent sites of transcriptional initiation were 97 and 96 bp upstream of the start codon for areC, near a sigma(54)-dependent -12, -24 promoter. Inactivation of areR and rpoN (for RNA polymerase sigma(54)) drastically reduced growth rates on the Are substrates and induction of the operon.
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Johnson LL, Schofield LM, Verdesca SA, Sharaf BL, Jones RM, Virmani R, Khaw BA. In vivo uptake of radiolabeled antibody to proliferating smooth muscle cells in a swine model of coronary stent restenosis. J Nucl Med 2000; 41:1535-40. [PMID: 10994735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
UNLABELLED Z2D3 is a monoclonal chimeric antibody fragment that is directed against a protein expressed on the surface of proliferating smooth muscle cells. The purpose of this study was to investigate the uptake of 111In-labeled Z2D3 F(ab')2 in a swine model of coronary neointimal proliferation after overexpansion coronary stenting. METHODS Twenty-two domestic swine underwent overexpansion coronary stenting of 2 vessels. Fifteen swine survived 2-4 wk, at which time they received an injection of 111In Z2D3 F(ab')2 and underwent planar imaging. After the swine were killed, the hearts were excised and imaged on the detector. The cross-sectional area of each stented vessel was measured with digital morphometry. RESULTS Pathology could be correlated with imaging for 24 vessels. The cross-sectional area of stenosis comprising neointimal proliferation ranged from 8% to 95%, with a mean +/- SD of 41% +/- 21%. The maximal stenosis ranged from 13% to 95%, with a mean of 51% +/- 20%. Seventeen of 24 vessels (71%) showed focal uptake on in vivo imaging, and 7 of 24 (29%) did not. Twenty of 24 (83%) showed uptake on ex vivo imaging. Of 11 stented vessels with maximal vessel stenosis less than 50%, 7 (64%) showed uptake both in vivo and ex vivo, and of 13 stented vessels with maximal vessel stenosis greater than 50%, 10 (77%) showed uptake both in vivo and ex vivo. CONCLUSION Uptake of a radiolabeled antibody directed against a component of proliferating neointimal tissue can be visualized in the coronary arteries on in vivo imaging using a scintillation gamma camera.
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Abstract
There are approximately 500 species of predatory cone snails within the genus Conus. They comprise what is arguably the largest single genus of marine animals alive today. It has been estimated that the venom of each Conus species has between 50 and 200 components. These highly constrained sulfur rich components or conotoxins represent a unique arsenal of neuropharmacologically active peptides that have been evolutionarily tailored to afford unprecedented and exquisite selectivity for a wide variety of ion-channel subtypes. Remarkable divergence occurs when cone snails speciate. Consequently, the complement of venom peptides in any one Conus species is distinct from that of any other species. Hence many thousands of peptides that modulate ion channel function are present within Conus venoms. Evolutionary pressures have afforded a "pre-optimized," structurally sophisticated library that has been "fine tuned" over 50 million years. The statistics associated with sampling such libraries bear testimony to the validity and feasibility of this strategy. Although approximately 100 conotoxin sequences have been published in the scientific literature, representing a mere 0.2 % of the estimated library size, this sample has already afforded a peptide of proven clinical utility and several pre-clinical leads for CNS disorders. Conus libraries represent a rich pharmacopoeia and the potential to "therapeutically mine" such a resource appears limitless. The paucity of synthetic methodologies necessary to achieve the regioisomeric folding patterns present in these native peptides precludes access to synthetic conotoxin libraries, further validating the overall "mining" strategy. In this article, we will present a pragmatic overview of the molecular diversity as well as the neurobiological mechanisms that define each major class of conotoxin.
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Stevens WC, Jones RM, Subramanian G, Metzger TG, Ferguson DM, Portoghese PS. Potent and selective indolomorphinan antagonists of the kappa-opioid receptor. J Med Chem 2000; 43:2759-69. [PMID: 10893314 DOI: 10.1021/jm0000665] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The indole moiety in the delta-opioid antagonist, naltrindole (2, NTI), was employed as a scaffold to hold an "address" for interaction with the kappa-opioid receptor. The attachment of the address to the 5'-position of the indole moiety was based on superposition of NTI upon the kappa antagonist, norbinaltorphimine (1, norBNI). A variety of cationic groups were employed as a kappa address in an effort to investigate its interaction with the anionic address subsite, Glu297, on the kappa receptor. Some of the groups that were employed for this purpose were amines, amidines, guanidines, and quaternary ammonium. Members of the series were found to have a varying degree of kappa antagonist potency and kappa selectivity when tested in smooth muscle preparations. The 5'-guanidine derivative 12a (GNTI) was the most potent member of the series and had the highest kappa selectivity ratio. GNTI was 2 times more potent and 6-10-fold more selective than norBNI (1). In general, the order of potency in the series was: guanidines > amidines approximately quaternary ammonium > amines. The kappa antagonist potency appeared to be a function of a combination of the pK(a) and distance constraint of the cationic substituent of the ligand. Receptor binding studies were qualitatively in agreement with the pharmacological data. Molecular modeling studies on 12a suggested that the protonated N-17 and guanidinium groups of GNTI are associated with Asp138 (TM3) and Glu297 (TM6), respectively, while the phenolic hydroxyl may be involved in donor-acceptor interactions with the imidazole ring of His291. It was concluded that the basis for the high kappa selectivity of GNTI is related both to association with the nonconserved Glu297 residue and to unfavorable interactions with an equivalent position in mu- and delta-opioid receptors.
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Jones RM, Portoghese PS. 5'-Guanidinonaltrindole, a highly selective and potent kappa-opioid receptor antagonist. Eur J Pharmacol 2000; 396:49-52. [PMID: 10822054 DOI: 10.1016/s0014-2999(00)00208-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
5'-Guanidinonaltrindole (GNTI) possesses 5-fold greater opioid antagonist potency (K(e)=0.04 nM) and an order of magnitude greater selectivity (selectivity ratios >500) than the prototypical kappa-opioid receptor antagonist, norbinaltorphimine, in smooth muscle preparations. Binding and functional studies conducted on cloned human opioid receptors expressed in Chinese hamster ovarian (CHO) cells afforded pA(2) values that were comparable to the smooth muscle data. In view of the high selectivity and potency of GNTI, it is a potentially valuable pharmacological tool for opioid research.
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Jones RM. Lumbar epidurals via the midline approach. Paediatr Anaesth 2000; 10:225. [PMID: 10787268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Larson DL, Jones RM, Hjorth SA, Schwartz TW, Portoghese PS. Binding of norbinaltorphimine (norBNI) congeners to wild-type and mutant mu and kappa opioid receptors: molecular recognition loci for the pharmacophore and address components of kappa antagonists. J Med Chem 2000; 43:1573-6. [PMID: 10780914 DOI: 10.1021/jm000059g] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Molecular modifications of both the kappa opioid antagonist norbinaltorphimine (norBNI, 1) and the kappa receptor have provided evidence that the selectivity of this ligand is conferred through ionic interaction if its N17' protonated amine group (an "address") with a nonconserved acidic residue (Glu297) on the kappa receptor. In the present study, we have examined the effect of structural modifications on the affinity of norBNI analogues for wild-type and mutant kappa and mu opioid receptors expressed in COS-7 cells. Compounds 2, 3, and 7, which have an antagonist pharmacophore and basic N17' group in common with norBNI, retained high affinity for the wild-type kappa but exhibited greatly reduced affinity for mutant kappa receptors (E297K and E297A). Modification of the phenolic or N-substituent groups of the antagonist pharmacophore (4 and 5) or removal of basicity at the address N17' center (6) led to greatly reduced affinity for the wild-type and mutant receptors. The reduced affinity upon modification of the kappa receptor is consistent with the ionic interaction of the protonated N17' group of kappa antagonists (1-3, 7) with the carboxylate group of E297 at the top of TM6. This was supported by the greatly enhanced affinity of compounds 1-3 for the mutant mu receptor (K303E), as compared to the wild-type mu receptor, given that residue K303 occupies a position equivalent to that of E297 in the kappa receptor. In view of the high degree of homology of the seven TM domains of the kappa and mu opioid receptors, it is suggested that the antagonist pharmacophore is bound within this highly conserved region of the kappa or mutant mu receptor and that an anionic residue at the top of TM6 (E297 or K303E, respectively) provides additional binding affinity.
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MESH Headings
- Amino Acid Substitution
- Animals
- COS Cells
- Cloning, Molecular
- Glutamic Acid/chemistry
- Ligands
- Models, Molecular
- Mutagenesis, Site-Directed
- Naltrexone/analogs & derivatives
- Naltrexone/chemistry
- Naltrexone/metabolism
- Narcotic Antagonists/chemistry
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/genetics
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, mu/genetics
- Receptors, Opioid, mu/metabolism
- Structure-Activity Relationship
- Transfection
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Jones RM, Pagmantidis V, Williams PA. sal genes determining the catabolism of salicylate esters are part of a supraoperonic cluster of catabolic genes in Acinetobacter sp. strain ADP1. J Bacteriol 2000; 182:2018-25. [PMID: 10715011 PMCID: PMC101918 DOI: 10.1128/jb.182.7.2018-2025.2000] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A 5-kbp region upstream of the are-ben-cat genes was cloned from Acinetobacter sp. strain ADP1, extending the supraoperonic cluster of catabolic genes to 30 kbp. Four open reading frames, salA, salR, salE, and salD, were identified from the nucleotide sequence. Reverse transcription-PCR studies suggested that these open reading frames are organized into two convergent transcription units, salAR and salDE. The salE gene, encoding a protein of 239 residues, was ligated into expression vector pET5a. Its product, SalE, was shown to have esterase activity against short-chain alkyl esters of 4-nitrophenol but was also able to hydrolyze ethyl salicylate to ethanol and salicylic acid. A mutant of ADP1 with a Km(r) cassette introduced into salE had lost the ability to utilize only ethyl and methyl salicylates of the esters tested as sole carbon sources, and no esterase activity against ethyl salicylate could be detected in cell extracts. SalE was induced during growth on ethyl salicylate but not during growth on salicylate itself. salD encoded a protein of undetermined function with homologies to the Escherichia coli FadL membrane protein, which is involved in facilitating fatty acid transport, and a number of other proteins detected during aromatic catabolism, which may also function in hydrocarbon transport or uptake processes. A Km(r) cassette insertion in salD deleteriously affected cell growth and viability. The salA and salR gene products closely resemble two Pseudomonas proteins, NahG and NahR, respectively encoding salicylate hydroxylase and the LysR family regulator of both salicylate and naphthalene catabolism. salA was cloned into pUC18 together with salR and salE, and its gene product showed salicylate-inducible hydroxylase activity against a range of substituted salicylates, with the same relative specific activities as found in wild-type ADP1 grown on salicylate. Mutations involving insertion of Km(r) cassettes into salA and salR eliminated expression of salicylate hydroxylase activity and the ability to grow on either salicylate or ethyl salicylate. Studies of mutants with disruptions of genes of the beta-ketoadipate pathway with or without an additional salE mutation confirmed that ethyl salicylate and salicylate were channeled into the beta-ketoadipate pathway at the level of catechol and thence dissimilated by the cat gene products. SalR appeared to regulate expression of salA but not salE.
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McCurdy CR, Jones RM, Portoghese PS. Investigation of phenolic bioisosterism in opiates: 3-sulfonamido analogues of naltrexone and oxymorphone. Org Lett 2000; 2:819-21. [PMID: 10754685 DOI: 10.1021/ol005561+] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[formula: see text] The phenolic hydroxy group of opiate-derived ligands is of known importance for biological activity. On the basis of its putative role as a hydrogen-bonding donor in the interaction with opioid receptors, it was replaced with a sulfonamide group because of their similar pKa values. The first thebaine-derived 3-amino (8a, 8b) and subsequent sulfonamide analogues (10a, 10b) were synthesized from naltrexone (1a) and oxymorphone (1b) in a linear nine-step synthesis. The sulfonamides were tested in vitro and found inactive.
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Jones RM, Bulaj G. Conus peptides - combinatorial chemistry at a cone snail's pace. CURRENT OPINION IN DRUG DISCOVERY & DEVELOPMENT 2000; 3:141-154. [PMID: 19649846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Conotoxins, the disulfide-rich toxin components of venomous marine cone snails, have attracted a great deal of attention in recent years because of their demonstrated pharmacological receptor subtype selectivities and distinct potential for development as new central nervous system (CNS) therapeutics. This review highlights some of the recent advancements in this field and describes a selection of contemporary papers pertaining to regioselective strategies for the synthesis of disulfide bridges in conotoxins, as well as other small constrained peptides. Primarily, we have covered papers that have appeared in the scientific literature over the past two years. A number of comprehensive conotoxin literature reviews have appeared in recent times.
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Jones RM, Rothman MI, Gray WC, Zoarski GH, Mattox DE. Temporal lobe injury in temporal bone fractures. ARCHIVES OF OTOLARYNGOLOGY--HEAD & NECK SURGERY 2000; 126:131-5. [PMID: 10680862 DOI: 10.1001/archotol.126.2.131] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To determine the incidence of intracranial injury, specifically in the temporal lobe, in patients with longitudinal fractures of the temporal bone. DESIGN Prospective inception cohort. SETTING University of Maryland Division of Otolaryngology-Head and Neck Surgery and the Maryland Shock Trauma Center, Baltimore. PATIENTS Twenty-seven consecutive patients with unilateral or bilateral temporal bone fractures. MAIN OUTCOME MEASURES Evaluation of temporal bone and intracranial trauma using computed tomography (CT) and magnetic resonance imaging (MRI). RESULTS Of the 27 patients enrolled in the study, 12 had the complete battery of MRI, CT, and physical and audiological examinations. In all 12 patients, MRI demonstrated adjacent middle cranial fossa meningeal enhancement. Results of non-contrast-enhanced CT and MRI demonstrated ipsilateral temporal lobe contusions in 6 of the 13 fractures for an overall incidence of 46%. In addition, MRI demonstrated 4 cerebral contusions not seen in the results of non-contrast-enhanced CT. CONCLUSIONS While high-resolution CT remains the criterion standard for evaluation of temporal bone fractures, MRI revealed a higher incidence of related temporal lobe injuries. Magnetic resonance imaging data may be valuable in preoperative evaluation of patients who require surgical intervention through a middle cranial fossa approach to document pre-existing injury and potential morbidity before retraction of the middle cranial fossa dura mater and temporal lobe.
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McDaniel TF, Garner CD, Miller DL, Jones RM. Comparing periodontal disease in identical twins: a case report. JOURNAL OF DENTAL HYGIENE : JDH 2000; 73:30-5. [PMID: 10634119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Previous investigators have shown that numerous environmental and genetic variables may contribute to the pathogenesis of periodontal disease. This case report presents clinical and laboratory findings of a set of Caucasian female identical twins. One patient presented clinically with mild gingivitis and no clinical or radiographic signs of periodontitis. The other exhibited gingivitis with localized, moderate-to-severe periodontitis. Neither patient reported a history of systemic conditions that might influence their periodontal health, and neither presented other known risk factors, such as tobacco use. The only apparent variable was related to their oral hygiene. The periodontally involved patient exhibited higher plaque scores than her twin in all clinical visits. Subgingival plaque cultures revealed the presence of Porphyromonas gingivalis and Bacteroides forsythus only in the diseased twin. Both patients had low colony counts of Prevotella intermedia and Eikenella corrodens, but only the healthy twin harbored small quantities of Fusobacterium nucleatum. This case report offers an opportunity to assess etiology of periodontitis in two genetically identical patients whose only obvious difference was their oral hygiene.
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Abstract
We present the case of a 20-month-old child who required admission to the intensive care with a presumptive diagnosis of acute laryngo-tracheo-bronchitis, for the management of acute upper airway obstruction. This child had received a complete course of Haemophilus influenzae type B (Hib) vaccine. Subsequent events showed that the diagnosis was not laryngo-tracheo-bronchitis but acute epiglottitis. We propose that a full course of vaccination is no guarantee against a subsequent illness with Hib and may actually lead to the wrong diagnosis and possibly life-threatening consequences.
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McCaughan GW, Spencer J, Koorey D, Bowden S, Bartholomeusz A, Littlejohn M, Verran D, Chui AK, Sheil AG, Jones RM, Locarnini SA, Angus PW. Lamivudine therapy in patients undergoing liver transplantation for hepatitis B virus precore mutant-associated infection: high resistance rates in treatment of recurrence but universal prevention if used as prophylaxis with very low dose hepatitis B immune globulin. LIVER TRANSPLANTATION AND SURGERY : OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION FOR THE STUDY OF LIVER DISEASES AND THE INTERNATIONAL LIVER TRANSPLANTATION SOCIETY 1999; 5:512-9. [PMID: 10545540 DOI: 10.1002/lt.500050601] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Recurrent hepatitis B virus (HBV) infection remains a major cause of morbidity and mortality after liver transplantation. Recently, antiviral therapy, such as lamivudine, has become available for prophylaxis against HBV reactivation posttransplantation and for the treatment of HBV recurrent disease. We report our initial experience with lamivudine therapy in patients with precore mutant-associated HBV infection undergoing liver transplantation (n = 29). Outcomes were compared in three patient groups: group 1, precore mutant HBV infection not receiving lamivudine (n = 10); group 2, recurrent precore mutant HBV infection posttransplantation subsequently treated with lamivudine (n = 10); and group 3, HBV precore mutant patients undergoing liver transplantation and receiving lamivudine and low-dose hepatitis B immune globulin (HBIG) from the time of transplantation (n = 9). In group 1, HBV recurred in 9 of 10 patients, with subsequent graft loss in all 9 patients. In group 2, all patients developed HBV recurrence at a mean of 7.3 months posttransplantation and started lamivudine therapy at a median of 16 months posttransplantation. Follow-up on lamivudine therapy was for a median of 11 months. Six of these 10 patients developed mutations in the HBV polymerase gene associated with lamivudine resistance. There were two liver failure-related deaths in this group. In group 3 patients, there was one death from graft-versus-host disease. The remaining 8 patients have been followed up for a mean of 15.6 months posttransplantation, and all remain hepatitis B surface antigen negative and HBV DNA negative. In conclusion, lamivudine therapy in association with low-dose HBIG is effective in preventing HBV reactivation posttransplantation. Rescue therapy with lamivudine in patients with HBV recurrence is only moderately effective, with a 60% lamivudine resistance rate in patients treated for longer than 6 months.
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Khan ZP, Munday IT, Jones RM, Thornton C, Mant TG, Amin D. Effects of dexmedetomidine on isoflurane requirements in healthy volunteers. 1: Pharmacodynamic and pharmacokinetic interactions. Br J Anaesth 1999; 83:372-80. [PMID: 10655905 DOI: 10.1093/bja/83.3.372] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Dexmedetomidine is a highly selective alpha 2-adrenoceptor agonist with anaesthetic-sparing effects. We have determined the pharmacodynamic and pharmacokinetic interactions between dexmedetomidine and isoflurane in volunteers. Nine male subjects were allocated randomly to receive isoflurane anaesthesia preceded by infusion of dexmedetomidine on three separate occasions, 2 weeks apart. Dexmedetomidine target plasma concentrations were 0.0 (placebo), 0.3 ng ml-1 (low-dex) and 0.6 ng ml-1 (high-dex). End-tidal isoflurane concentrations at which gross purposeful movement and response to verbal commands occurred were identified. In the recovery period, sedation scores and digit symbol substitution tests were recorded. Venous blood samples were obtained before, during and after anaesthesia at predetermined intervals for measurement of plasma concentrations of dexmedetomidine and calculation of standard pharmacokinetic indices (AUC, Cl, Vss, T1/2 alpha, T1/2 beta). The end-tidal isoflurane concentration at which 50% of subjects first responded to the tetanic stimulus was 1.05% in the placebo group, 0.72% in the low-dex group and 0.52% in the high-dex group. We conclude that dexmedetomidine decreased isoflurane requirements in a dose-dependent manner and reduced heart rate, systolic and diastolic arterial pressures. Sedation and slight impairment of cognitive function persisted for several hours after anaesthesia and the end of infusion of dexmedetomidine. Isoflurane did not appear to influence the pharmacokinetics of dexmedetomidine.
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Keogh JB, Tsalamandris C, Sewell RB, Jones RM, Angus PW, Nyulasi IB, Seeman E. Bone loss at the proximal femur and reduced lean mass following liver transplantation: a longitudinal study. Nutrition 1999; 15:661-4. [PMID: 10467609 DOI: 10.1016/s0899-9007(99)00121-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The longevity of recipients of liver transplant may be compromised by spinal osteoporosis and vertebral fractures. However, femoral neck fractures are associated with a higher morbidity and mortality than spine fractures. As there is little information on bone loss at this clinically important site of fracture, the aim of this study was to determine whether accelerated bone loss occurs at the proximal femur following transplantation. Bone mineral density and body composition were measured at the femoral neck, lumbar spine and total body, using dual x-ray absorptiometry in 22 men and 19 women, age 46 +/- 1.4 y (mean +/- SEM) before and at a mean of 19 mo after surgery (range 3-44). Results were expressed in absolute terms (g/cm2) and as a z score. Before transplantation, z scores for bone mineral density were reduced at the femoral neck (-0.47 +/- 0.21 SD), trochanter (-0.56 +/- 0.19 SD), Ward's triangle (-0.35 +/- 0.14 SD), lumbar spine (-0.76 +/- 0.13 SD), and total body (-0.78 +/- 0.15 SD) (all P < 0.01 to < 0.001). Following transplantation, bone mineral density decreased by 8.0 +/- 1.7% at the femoral neck (P < or = 0.01) and by 2.0 +/- 1.2% at the lumbar spine (P < or = 0.05). Total weight increased by 12.2 +/- 2.3%, lean mass decreased by 5.7 +/- 1.4%, while fat mass increased from 24.1 +/- 2.0% to 35.1 +/- 1.8% (all P < or = 0.001). Patients with end-stage liver disease have reduced bone mineral density. Liver transplantation is associated with a rapid decrease in bone mineral density at the proximal femur, further increasing fracture risk and a reduction in lean (muscle) mass, which may also predispose to falls. Prophylactic therapy to prevent further bone loss should be considered in patients after liver transplantation.
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Thornton C, Lucas MA, Newton DE, Doré CJ, Jones RM. Effects of dexmedetomidine on isoflurane requirements in healthy volunteers. 2: Auditory and somatosensory evoked responses. Br J Anaesth 1999; 83:381-6. [PMID: 10655906 DOI: 10.1093/bja/83.3.381] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The anaesthetic-sparing activity of dexmedetomidine during isoflurane anaesthesia was examined, using the end-point of lack of response to tetanic nerve stimulation. Nine subjects were given two doses of dexmedetomidine (target plasma concentrations of 0.3 ng ml-1 and 0.6 ng ml-1, respectively) and saline on separate occasions. We measured auditory (AER) and somatosensory (SER) evoked responses at end-tidal isoflurane concentrations of 0.2-1.4%. Pa and P25-N35 amplitudes increased as isoflurane concentration was reduced (P < 0.001). Dexmedetomidine had no significant effect on this relationship. In contrast, P15-N20 (SER) amplitude increased (P < 0.001) as isoflurane concentration was reduced. The dose of dexmedetomidine had a significant interaction with this trend (P < 0.002). Decreasing the concentration of isoflurane at the high dose of dexmedetomidine had less impact on P15-N20 amplitude than decreasing isoflurane at the low dose or with saline. The mechanism by which dexmedetomidine spares isoflurane is discussed in the light of these evoked response changes.
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Jones RM, Collier LS, Neidle EL, Williams PA. areABC genes determine the catabolism of aryl esters in Acinetobacter sp. Strain ADP1. J Bacteriol 1999; 181:4568-75. [PMID: 10419955 PMCID: PMC103588 DOI: 10.1128/jb.181.15.4568-4575.1999] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acinetobacter sp. strain ADP1 is able to grow on a range of esters of aromatic alcohols, converting them to the corresponding aromatic carboxylic acids by the sequential action of three inducible enzymes: an areA-encoded esterase, an areB-encoded benzyl alcohol dehydrogenase, and an areC-encoded benzaldehyde dehydrogenase. The are genes, adjacent to each other on the chromosome and transcribed in the order areCBA, were located 3.5 kbp upstream of benK. benK, encoding a permease implicated in benzoate uptake, is at one end of the ben-cat supraoperonic cluster for benzoate catabolism by the beta-ketoadipate pathway. Two open reading frames which may encode a transcriptional regulator, areR, and a porin, benP, separate benK from areC. Each are gene was individually expressed to high specific activity in Escherichia coli. The relative activities against different substrates of the cloned enzymes were, within experimental error, identical to that of wild-type Acinetobacter sp. strain ADP1 grown on either benzyl acetate, benzyl alcohol, or 4-hydroxybenzyl alcohol as the carbon source. The substrate preferences of all three enzymes were broad, encompassing a range of substituted aromatic compounds and in the case of the AreA esterase, different carboxylic acids. The areA, areB, and areC genes were individually disrupted on the chromosome by insertion of a kanamycin resistance cassette, and the rates at which the resultant strains utilized substrates of the aryl ester catabolic pathway were severely reduced as determined by growth competitions between the mutant and wild-type strains.
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Shiotani A, Jones RM, Flint PW. Postnatal development of myosin heavy chain isoforms in rat laryngeal muscles. Ann Otol Rhinol Laryngol 1999; 108:509-15. [PMID: 10335716 DOI: 10.1177/000348949910800517] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The developmental transitions of myosin heavy chain (MHC) isoforms of rat posterior cricoarytenoid (PCA), thyroarytenoid (TA), cricothyroid (CT), and lateral cricoarytenoid (LCA) muscles were examined by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot techniques. The muscles were microscopically dissected from animals on postnatal days 0, 3, 7, 10, 14, 21, 28, 35, 45, and 55 and from adult animals. Silver-stained SDS-PAGE gels of each muscle were analyzed densitometrically to measure the composition of MHC isoforms, and Western blot was carried out to identify specific bands. Characterizations of the internal laryngeal muscles determined by the composition of MHCs were correlated with their function in the adult. Temporally, differentiation reflects onset of function. Differentiation of isoforms and transition to adult forms occur first in the TA muscle, followed by the PCA, LCA, and CT muscles. Expression of type IIL was observed only in muscles innervated by the recurrent laryngeal nerve. Postnatally observed developmental differences of myosin phenotypes suggest that regulation of MHC expression is influenced by neural activity or other environmental factors.
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Virmani R, Kolodgie FD, Dake MD, Silver JH, Jones RM, Jenkins M, Gillespie DL. Histopathologic evaluation of an expanded polytetrafluoroethylene-nitinol stent endoprosthesis in canine iliofemoral arteries. J Vasc Interv Radiol 1999; 10:445-56. [PMID: 10229474 DOI: 10.1016/s1051-0443(99)70064-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
PURPOSE The authors assess a new ePTFE-nitinol stent for its long-term patency, healing, and properties of endothelialization. MATERIALS AND METHODS Adult greyhounds (n = 18) underwent bilateral iliofemoral placement of an endoprosthesis (Hemobahn) consisting of a nitinol stent lined with an ultrathin expanded polytetrafluoroethylene (ePTFE) material. Histologic and quantitative morphometric analyses were performed on devices explanted at 2 weeks and 1, 3, 6, and 12 months. The source of endothelialization was examined in four additional devices modified by sealing either the proximal and distal ends or the entire graft with poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP), a nonporous laminate to prevent potential transgraft endothelial cell migration. RESULTS Device patency assessed with both intravascular ultrasound and histologic study showed minimal arterial stenosis, irrespective of implant duration. The neointima at less than 3 months consisted of fibrin and inflammatory infiltrate; at later time points, it was composed of mostly smooth muscle cells. Flow surfaces were more than 75% endothelialized by 3 months, which was nearly complete by 6 months. Modified endoprostheses entirely enveloped with FEP resulted in endothelialization of only the proximal and distal ends; the middle regions showed nonocclusive thrombi. Conversely, devices wrapped proximally and distally showed nearly complete endothelialization. CONCLUSIONS This ePTFE-nitinol endoprosthesis demonstrated long-term patency at up to 1 year after implantation and showed early and nearly complete endothelialization by 6 months. The design promoted rapid endothelialization of flow surfaces, particularly in the midregion of the device possibly by transgraft migration.
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Hewitt CR, Foster S, Phillips C, Horton H, Jones RM, Brown AP, Hart BJ, Pritchard DI. Mite allergens: significance of enzymatic activity. Allergy 1999; 53:60-3. [PMID: 10096811 DOI: 10.1111/j.1398-9995.1998.tb05000.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ten years ago, the cloning and sequencing of a cDNA encoding the group I allergen of house-dust mites unequivocally determined that protein allergens may have biochemical functions in addition to their ability to bind IgE. Since this discovery, several groups have speculated that the biochemical activities of allergens, or substances associated with allergens, may be involved in their immunogenicity or allergenicity. This paper will focus on just one biochemical function, proteolytic activity, and will be illustrated by examples of our own work that we believe support the hypothesis that this category of molecules are endowed with the properties of proallergic adjuvants.
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Khan ZP, Ferguson CN, Jones RM. alpha-2 and imidazoline receptor agonists. Their pharmacology and therapeutic role. Anaesthesia 1999; 54:146-65. [PMID: 10215710 DOI: 10.1046/j.1365-2044.1999.00659.x] [Citation(s) in RCA: 407] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Clonidine has proved to be a clinically useful adjunct in clinical anaesthetic practice as well as in chronic pain therapy because it has both anaesthetic and analgesic-sparing activity. The more selective alpha-2 adrenoceptor agonists, dexmedetomidine and mivazerol, may also have a role in providing haemodynamic stability in patients who are at risk of peri-operative ischaemia. The side-effects of hypotension and bradycardia have limited the routine use of alpha-2 adrenoceptor agonists. Investigations into the molecular pharmacology of alpha-2 adrenoceptors have elucidated their role in the control of wakefulness, blood pressure and antinociception. We discuss the pharmacology of alpha-2 adrenoceptors and their therapeutic role in this review. The alpha-2 adrenoceptor agonists are agonists at imidazoline receptors which are involved in central blood pressure control. Selective imidazoline agonists are now available for clinical use as antihypertensive agents and their pharmacology is discussed.
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Jones RM, Yuan ZX, Lim CK. Tamoxifen metabolism in rat liver microsomes: identification of a dimeric metabolite derived from free radical intermediates by liquid chromatography/mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 1999; 13:211-215. [PMID: 10097399 DOI: 10.1002/(sici)1097-0231(19990228)13:4<211::aid-rcm436>3.0.co;2-l] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Tamoxifen has been shown to be a potent liver carcinogen in rats, and generates covalent DNA adducts. On-line high performance liquid chromatography/electrospray ionisation mass spectrometry (HPLC/ESI-MS) has been used to further study the metabolites of tamoxifen formed by rat liver microsomes in the presence of NADPH with a view to identifying potential reactive metabolites which may be responsible for the formation of DNA adducts, and liver carcinogenesis. A metabolite has been detected with a protonated molecule at m/z 773. The mass of this compound is consistent with a dimer of hydroxylated tamoxifen (m/z 388). Analysis of 4-hydroxytamoxifen incubated with a rat liver microsomal preparation showed the formation of a similar metabolite with an apparent MH+ ion at m/z 773, believed to be a dimer of 4-hydroxytamoxifen formed by a free radical reaction. The retention time for this metabolite from 4-hydroxytamoxifen is identical to that of the tamoxifen metabolite, suggesting that these two compounds are the same. The levels of the dimer were higher when 4-hydroxytamoxifen was used as substrate and, in addition, two isomers were detected. It is proposed that tamoxifen was first converted to arene oxides which react with DNA or to 4-hydroxytamoxifen, either directly or via 3,4-epoxytamoxifen, which then undergoes activation via a free radical reaction to give reactive intermediates which can then react with DNA and protein, or with themselves, to give the dimers (m/z 773).
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Soliman AM, Jones RM, Flint PW. Cell adhesion molecules in normal laryngeal development. Otolaryngol Head Neck Surg 1999; 120:73-7. [PMID: 9914552 DOI: 10.1016/s0194-5998(99)70372-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Larynges taken from normally developing rats ranging from embryos starting at embryonic day 10 to adults were harvested. Sections of the larynges were prepared with the use of immunohistochemical techniques with primary antibodies directed to the neural cell adhesion molecule; selected sections were exposed to antibodies directed against the embryonic polysialated form of the neural cell adhesion molecule and against L1. Cell adhesion molecules were present throughout embryonic development associated with the recurrent laryngeal nerve. Downregulation of expression was observed after postnatal day 14. We conclude that cell adhesion molecules may play a role in the normal neural development of the larynx in rats.
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Virmani R, Farb A, Carter AJ, Jones RM. Pathology of radiation-induced coronary artery disease in human and pig. CARDIOVASCULAR RADIATION MEDICINE 1999; 1:98-101. [PMID: 11272363 DOI: 10.1016/s1522-1865(98)00010-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE External beam mediastinal radiation-induced accelerated coronary atherosclerotic heart disease in humans has been recognized, especially when the condition occurs in young persons. The purpose of the present study was to compare external beam radiation-induced accelerated coronary atherosclerosis in humans with that seen in the pig coronary arteries following radioactive stent placement. METHODS A literature review of radiation-induced coronary artery disease was performed. In addition, clinical records and coronary histology from the Armed Forces Institute of Pathology Registry were reviewed from patients who had received external beam radiation for mediastinal malignancies. Coronary arteries from pigs that had radioactive coronary stent placement were evaluated from our stent pathology laboratory and analyzed for comparison with the human disease. RESULTS In humans, the characteristics of the intimal plaque in accelerated atherosclerosis postradiation therapy were similar to that seen in typical atherosclerotic coronary disease in the absence of radiation therapy. However, medial thinning and adventitial fibrosis were the distinguishing pathologic arterial changes secondary to radiation seen in humans. Radioactive stent placement in pig coronary arteries produced similar changes to that observed in humans post-external beam radiation, consisting of medial injury and adventitial thickening accompanied by intimal foam cell collections, calcification, and necrotic core formation containing cholesterol clefts resulting in severe luminal narrowing. CONCLUSIONS Radiation, delivered via external beam or radioactive stent, induces changes of intimal atherosclerosis with medial thinning and adventitial scarring in human and pig. Therefore, pending completion of long-term clinical studies, caution should be exercised before the widespread use of brachytherapy is advocated for the treatment and prevention of coronary restenosis.
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