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DiNicolantonio JJ, Fares H, Niazi AK, Chatterjee S, D'Ascenzo F, Cerrato E, Biondi-Zoccai G, Lavie CJ, Bell DS, O'Keefe JH. β-Blockers in hypertension, diabetes, heart failure and acute myocardial infarction: a review of the literature. Open Heart 2015; 2:e000230. [PMID: 25821584 PMCID: PMC4371808 DOI: 10.1136/openhrt-2014-000230] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 01/16/2015] [Accepted: 02/15/2015] [Indexed: 11/12/2022] Open
Abstract
β-Blockers (BBs) are an essential class of cardiovascular medications for
reducing morbidity and mortality in patients with heart failure (HF). However, a
large body of data indicates that BBs should not be used as first-line therapy for
hypertension (HTN). Additionally, new data have questioned the role of BBs in the
treatment of stable coronary heart disease (CHD). However, these trials mainly tested
the non-vasodilating β1 selective BBs (atenolol and metoprolol)
which are still the most commonly prescribed BBs in the USA. Newer generation BBs,
such as the vasodilating BBs carvedilol and nebivolol, have been shown not only to be
better tolerated than non-vasodilating BBs, but also these agents do not increase the
risk of diabetes mellitus (DM), atherogenic dyslipidaemia or weight gain. Moreover,
carvedilol has the most evidence for reducing morbidity and mortality in patients
with HF and those who have experienced an acute myocardial infarction (AMI). This
review discusses the cornerstone clinical trials that have tested BBs in the settings
of HTN, HF and AMI. Large randomised trials in the settings of HTN, DM and stable CHD
are still needed to establish the role of BBs in these diseases, as well as to
determine whether vasodilating BBs are exempt from the disadvantages of
non-vasodilating BBs.
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Gritti F, Bell DS, Guiochon G. Particle size distribution and column efficiency. An ongoing debate revived with 1.9μm Titan-C18 particles. J Chromatogr A 2014; 1355:179-92. [DOI: 10.1016/j.chroma.2014.06.029] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 06/06/2014] [Accepted: 06/10/2014] [Indexed: 10/25/2022]
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Li X, Uboh CE, Soma LR, Liu Y, Guan F, Aurand CR, Bell DS, You Y, Chen J, Maylin GA. Sensitive hydrophilic interaction liquid chromatography/tandem mass spectrometry method for rapid detection, quantification and confirmation of cathinone-derived designer drugs for doping control in equine plasma. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014; 28:217-229. [PMID: 24338970 DOI: 10.1002/rcm.6778] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 10/29/2013] [Accepted: 10/31/2013] [Indexed: 06/03/2023]
Abstract
RATIONALE Cathinone derivatives are new amphetamine-like stimulants that can evade detection when presently available methods are used for doping control. To prevent misuse of these banned substances in racehorses, development of a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method became the impetus for undertaking this study. METHODS Analytes were recovered via liquid-liquid extraction using methyl tert-butyl ether. Analyte separation was achieved on a hydrophilic interaction column using liquid chromatography and mass analysis was performed on a QTRAP mass spectrometer in positive electrospray ionization (ESI) mode with multiple reaction monitoring (MRM). Analyte identification was carried out by screening for a specified MRM transition. Quantification was conducted using an internal standard. Confirmation was performed by establishing a match in retention time and ion intensity ratios comparison. RESULTS The method was linear over the range 0.2-50 ng/mL. The specificity was evaluated by analysis of six different batches of blank plasma and those spiked with each analyte (0.2 ng/mL). The recovery of analytes from plasma at three different concentrations was >70%. The limits of detection, quantification and confirmation were 0.02-0.05, 0.2-1.0 and 0.2-10 ng/mL, respectively. The matrix effect was insignificant. The intra-day and inter-day precision were 1.94-12.08 and 2.58-13.32%, respectively. CONCLUSIONS The method is routinely employed in screening for the eleven analytes in post-competition samples collected from racehorses in Pennsylvania to enforce the ban on the use of these performance-enhancing agents in racehorses. The method is sensitive, fast, effective and reliably reproducible.
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Kotoni D, Ciogli A, Villani C, Bell DS, Gasparrini F. Separation of complex sugar mixtures on a hydrolytically stable bidentate urea-type stationary phase for hydrophilic interaction near ultra high performance liquid chromatography. J Sep Sci 2014; 37:527-35. [DOI: 10.1002/jssc.201301008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 12/09/2013] [Accepted: 12/14/2013] [Indexed: 11/08/2022]
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Kotoni D, Villani C, Bell DS, Capitani D, Campiglia P, Gasparrini F. Bidentate urea-based chiral selectors for enantioselective high performance liquid chromatography: Synthesis and evaluation of “Crab-like” stationary phases. J Chromatogr A 2013; 1297:157-67. [DOI: 10.1016/j.chroma.2013.04.083] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 04/24/2013] [Accepted: 04/29/2013] [Indexed: 11/15/2022]
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Brown MM, Bell DS, Jason LA, Christos C, Bell DE. Understanding long-term outcomes of chronic fatigue syndrome. J Clin Psychol 2012; 68:1028-35. [PMID: 22753044 DOI: 10.1002/jclp.21880] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE This study sought to examine long-term health, symptom, and disability outcomes among patients with chronic fatigue syndrome (CFS) by comparing those diagnosed with CFS 25 years ago with healthy controls. METHOD Of the 25 participants diagnosed with CFS 25 years ago, 5 self-reported that they maintained a diagnosis of CFS, while 20 reported no longer having a diagnosis. These two groups were compared with healthy controls on outcomes related to functioning and symptom severity. RESULTS Those who remitted from CFS showed significantly more impairment on 21 out of 23 outcomes compared with controls. On 17 outcomes, those who remitted had nonsignificant differences in impairment compared to those who maintained a CFS diagnosis. CONCLUSIONS Findings from this study suggest that over time many individuals will not maintain a CFS diagnosis but will not return to their premorbid level of functioning.
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Lee LL, Lin L, Bell DS, Levine S, Hanson MR. Sensitivity of PCR assays for murine gammaretroviruses and mouse contamination in human blood samples. PLoS One 2012; 7:e37482. [PMID: 22629404 PMCID: PMC3357399 DOI: 10.1371/journal.pone.0037482] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Accepted: 04/24/2012] [Indexed: 11/19/2022] Open
Abstract
Gammaretroviruses related to murine leukemia virus (MLV) have variously been reported to be present or absent in blood from chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) patients and healthy controls. Using subjects from New York State, we have investigated by PCR methods whether MLV-related sequences can be identified in nucleic acids isolated from whole blood or from peripheral blood mononuclear cells (PBMCs) or following PBMC culture. We have also passaged the prostate cancer cell line LNCaP following incubation with plasma from patients and controls and assayed nucleic acids for viral sequences. We have used 15 sets of primers that can effectively amplify conserved regions of murine endogenous and exogenous retrovirus sequences. We demonstrate that our PCR assays for MLV-related gag sequences and for mouse DNA contamination are extremely sensitive. While we have identified MLV-like gag sequences following PCR on human DNA preparations, we are unable to conclude that these sequences originated in the blood samples.
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Hanson MR, Lee LL, Lin L, Bell DE, Ruppert D, Bell DS. Detection of MLV-like gag sequences in blood samples from a New York state CFS cohort. Retrovirology 2011. [PMCID: PMC3112714 DOI: 10.1186/1742-4690-8-s1-a234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Carruthers BM, van de Sande MI, De Meirleir KL, Klimas NG, Broderick G, Mitchell T, Staines D, Powles ACP, Speight N, Vallings R, Bateman L, Baumgarten-Austrheim B, Bell DS, Carlo-Stella N, Chia J, Darragh A, Jo D, Lewis D, Light AR, Marshall-Gradisnik S, Mena I, Mikovits JA, Miwa K, Murovska M, Pall ML, Stevens S. Myalgic encephalomyelitis: International Consensus Criteria. J Intern Med 2011; 270:327-38. [PMID: 21777306 PMCID: PMC3427890 DOI: 10.1111/j.1365-2796.2011.02428.x] [Citation(s) in RCA: 701] [Impact Index Per Article: 53.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The label 'chronic fatigue syndrome' (CFS) has persisted for many years because of the lack of knowledge of the aetiological agents and the disease process. In view of more recent research and clinical experience that strongly point to widespread inflammation and multisystemic neuropathology, it is more appropriate and correct to use the term 'myalgic encephalomyelitis' (ME) because it indicates an underlying pathophysiology. It is also consistent with the neurological classification of ME in the World Health Organization's International Classification of Diseases (ICD G93.3). Consequently, an International Consensus Panel consisting of clinicians, researchers, teaching faculty and an independent patient advocate was formed with the purpose of developing criteria based on current knowledge. Thirteen countries and a wide range of specialties were represented. Collectively, members have approximately 400 years of both clinical and teaching experience, authored hundreds of peer-reviewed publications, diagnosed or treated approximately 50 000 patients with ME, and several members coauthored previous criteria. The expertise and experience of the panel members as well as PubMed and other medical sources were utilized in a progression of suggestions/drafts/reviews/revisions. The authors, free of any sponsoring organization, achieved 100% consensus through a Delphi-type process. The scope of this paper is limited to criteria of ME and their application. Accordingly, the criteria reflect the complex symptomatology. Operational notes enhance clarity and specificity by providing guidance in the expression and interpretation of symptoms. Clinical and research application guidelines promote optimal recognition of ME by primary physicians and other healthcare providers, improve the consistency of diagnoses in adult and paediatric patients internationally and facilitate clearer identification of patients for research studies.
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Jason L, Porter N, Shelleby E, Till L, Bell DS, Lapp CW, Rowe K, De Meirleir K. Severe versus Moderate criteria for the new pediatric case definition for ME/CFS. Child Psychiatry Hum Dev 2009; 40:609-20. [PMID: 19513826 DOI: 10.1007/s10578-009-0147-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Accepted: 05/25/2009] [Indexed: 10/20/2022]
Abstract
The new diagnostic criteria for pediatric ME/CFS are structurally based on the Canadian Clinical Adult case definition, and have more required specific symptoms than the (Fukuda et al. Ann Intern Med 121:953-959, 1994) adult case definition. Physicians specializing in pediatric ME/CFS referred thirty-three pediatric patients with ME/CFS and 21 youth without the illness. Those who met ME/CFS criteria were separated into Severe and Moderate categories. Significant differences were found for symptoms within each of the six major categories: fatigue, post-exertional malaise, sleep, pain, neurocognitive difficulties, and autonomic/neuroendocrine/immune manifestations. In general, the results showed participants who met the Severe ME/CFS criteria reported the highest scores, the Moderate ME/CFS group show scores that were a little lower, and the control group evidenced the lowest scores. Findings indicate that the Pediatric Case Definition for ME/CFS can distinguish between those with this illness and controls, and between those with Severe versus Moderate manifestations of the illness.
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Bell DS. Controversy Corner: Quieta movere magna merces videbatur: The Bite and Bark of Medico-Legal Argument. AUST J FORENSIC SCI 2009. [DOI: 10.1080/00450619609411356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Bell DS. Editorial. AUST J FORENSIC SCI 2009. [DOI: 10.1080/00450619609411345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Bell DS. Forensic Medicine and the Law. AUST J FORENSIC SCI 2009. [DOI: 10.1080/00450619609411358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Bell DS. Guide to the Seeker. AUST J FORENSIC SCI 2009. [DOI: 10.1080/00450619609411346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Bell DS. Guide to the Seeker. AUST J FORENSIC SCI 2009. [DOI: 10.1080/00450619909410780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Jason LA, Porter N, Shelleby E, Bell DS, Lapp CW, Rowe K, De Meirleir K. A Case Definition for Children with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. CLINICAL MEDICINE. PEDIATRICS 2008. [DOI: 10.4137/cmped.s978] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The case definition for chronic fatigue syndrome was developed for adults (Fukuda et al. 1994), and this case definition may not be appropriate for use with children and adolescents. The lack of application of a consistent pediatric definition for this illness and the lack of a reliable instrument to assess it might lead to studies which lack sensitivity and specificity. In this article, a case definition is presented that has been endorsed by the International Association of ME/CFS.
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Nuckols TK, Bell DS, Paddock SM, Hilborne LH. Contributing factors identified by hospital incident report narratives. Qual Saf Health Care 2008; 17:368-72. [DOI: 10.1136/qshc.2007.023721] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Bell DS. Science at law. AUST J FORENSIC SCI 2007. [DOI: 10.1080/00450610701324940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Brondz I, Ekeberg D, Høiland K, Bell DS, Annino AR. The real nature of the indole alkaloids in Cortinarius infractus: Evaluation of artifact formation through solvent extraction method development. J Chromatogr A 2007; 1148:1-7. [PMID: 17391682 DOI: 10.1016/j.chroma.2007.02.074] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Revised: 02/07/2007] [Accepted: 02/14/2007] [Indexed: 11/28/2022]
Abstract
This study was triggered by the absence of infractine in EtOH extracts of Cortinarius infractus and the presence of the beta-carboline-1-propionic acid [I. Brondz, K. Høiland, D.S. Bell, A.R. Annino, TheReporter, Supelco 24 (3) (2006) 6]. In previous studies it was determined that C. infractus contained indole alkaloid substances of the infractine group [W. Steglich, L. Kopanski, M. Wolf, M. Moser, G. Tegtmeyer, Indolalkaloide aus dem Blaetterpilz Cortinarius infractus (Agaricales). Tetrahedron Lett. 25 (1984) 2341]. It is quite possible that some of these compounds do not exist in any other mushroom species and therefore they could prove to be valuable chemotaxonomic markers. Proper classification of this species requires that the chemical markers are identified correctly. In this study, the presence of several compounds previously found in C. infractus (Pers.: Fr.) Fr. is questioned. In this investigation, it was shown by HPLC-MS that infractine and 6-hydroxyinfractine, previously described as constituents of C. infractus, were artifacts produced during the extraction process. Also, the molecular species that participate in the artefact formation were identified. Infractine and 6-hydroxyinfractine, reported earlier in C. infractus, originate from the precursor (pre-infractine) beta-carboline-1-propionic acid during extraction with methanol.
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Brondz I, Ekeberg D, Bell DS, Annino AR, Hustad JA, Svendsen R, Vlachos V, Oakley P, Langley GJ, Mohini T, Amaury CG, Mikhalitsyn F. Nature of the main contaminant in the drug primaquine diphosphate: SFC and SFC–MS methods of analysis. J Pharm Biomed Anal 2007; 43:937-44. [PMID: 17079107 DOI: 10.1016/j.jpba.2006.09.017] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Revised: 09/07/2006] [Accepted: 09/08/2006] [Indexed: 11/15/2022]
Abstract
The drug primaquine diphosphate is used for causative treatment of malaria. Using HPLC-MS and GC-MS, this research group was previously able to show that the main contaminant of primaquine is the positional isomer quinocide [I. Brondz, D. Mantzilas, U. Klein, D. Ekeberg, E. Hvattum, M.N. Lebedeva, F.S. Mikhailitsyn, G.D. Soulimanov, J. Roe, J. Chromatogr. B: Anal. Technol. Biomed. Life Sci. 800 (2004) 211-223; I. Brondz, U. Klein, D. Ekeberg, D. Mantzilas, E. Hvattum, H. Schultz, F. S. Mikhailitsyn, Asian J. Chem. 17 (2005) 1678-1688]. Primaquine and quinocide are highly toxic substances which can have a number of side effects upon use in medical treatment. A standard for quinocide is not typically commercially available. In the present work, supercritical fluid chromatography-mass spectrometry (SFC-MS) with two different columns was used to achieve a shorter analysis time for the separation between the positional isomers quinocide and primaquine in primaquine diphosphate and to elucidate additional information about differences in their MS fragmentation. Unlike using HPLC-MS, it was possible to achieve the differential fragmentation of positional isomers at branching points using the SFC-MS technique. The desired short analysis time was achieved using SFC equipped with a Discovery HS F5 column and the differential fragmentation of positional isomers during SFC-MS provides information on the differences in the structure of these substances. Using a Chiralpak AD-H chiral column, it was possible to resolve the enantiomers in primaquine and separate quinocide from those enantiomers.
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Bell DS. Controversy Corner: Quieta movere magna merces videbatur. AUST J FORENSIC SCI 2006. [DOI: 10.1080/00450610609410637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Bell DS, Cramer HM, Jones AD. Rational method development strategies on a fluorinated liquid chromatography stationary phase: Mobile phase ion concentration and temperature effects on the separation of ephedrine alkaloids. J Chromatogr A 2005; 1095:113-8. [PMID: 16275290 DOI: 10.1016/j.chroma.2005.08.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2005] [Revised: 07/29/2005] [Accepted: 08/01/2005] [Indexed: 11/24/2022]
Abstract
Fluorinated, silica-based stationary phases are becoming increasingly popular alternatives to traditional alkyl phases owing to their differential selectivity and retention for a variety of analyte classes. In this report, the ion-exchange mechanisms characteristic of a fluorinated phase are exploited to rapidly develop separation conditions for ephedrine alkaloids and synephrine using a mobile phase compatible with mass spectrometry. A linear relationship of basic analyte retention with the reciprocal of ammonium acetate concentration is first established. This linear relationship can then be used to optimize retention and selectivity in just two experiments. The relationship of retention with temperature is also explored. Greater retention with increasing temperature is demonstrated on the fluorinated phase at high percentages of organic modifier, which is in contrast to behavior observed in typical reversed-phase separations. The unexpected observation is explicated based on the reduction in solvent solvating power with increasing temperature. As solvation power of the mobile phase decreases, decreased solvation of both mobile phase and ionized surface groups of the stationary phase leads to stronger interactions between analyte and stationary phase. Both mobile phase ion concentration and temperature are shown to be powerful tools for the manipulation of analyte retention and selectivity.
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Bell DS. Book Review. AUST J FORENSIC SCI 2005. [DOI: 10.1080/00450610509410622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Bell DS, Jones AD. Solute attributes and molecular interactions contributing to “U-shape” retention on a fluorinated high-performance liquid chromatography stationary phase. J Chromatogr A 2005; 1073:99-109. [PMID: 15909511 DOI: 10.1016/j.chroma.2004.08.163] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structural attributes and molecular interactions contributing to "U-shape" retention on pentafluorophenylpropyl (PFPP) HPLC stationary phases are systematically investigated. Only basic analytes exhibit retention that increases with the acetonitrile content in mixtures of acetonitrile and aqueous ammonium acetate, with some basic analytes not eluting at all from PFPP columns using 100% acetonitrile. U-shaped retention as a function of mobile phase acetonitrile content was more dramatic on a PFPP column relative to C18. Retention of the quaternary ammonium salt bretylium on these stationary phases and on the same bare silica support showed minimal influence of ion-exchange mechanisms on the C18 phase, however, a significant influence of ion-exchange mechanisms was observed for both PFPP and bare silica. The retention of bretylium on PFPP was only slightly less than on bare silica. These findings suggest ion-exchange mechanisms dominate retention of basic analytes in the high acetonitrile realm on PFPP. The PFPP stationary phase exhibits a substantial increase in effects of ionized surface silanol groups compared to the alkyl phase despite similar surface coverage. Retention of some basic analytes on a PFPP phase was enhanced relative to retention on silica alone, and implicates other dispersive interactions that might be exploited for selectivity different from either alkyl phases or silica alone.
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Bell DS, Ovalle F. C-Peptide utilization in clinical practice: effect on treatment and outcome of diabetes in a series of cases. Endocr Pract 2005; 5:114-8. [PMID: 15251680 DOI: 10.4158/ep.5.3.114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To emphasize that measurement of a C-peptide level can be critical in the diagnosis and appropriate management of patients with diabetes mellitus. METHODS We present a series of clinical cases in which glycemic control proved challenging, and we discuss the underlying pathophysiologic features of type 1 versus type 2 diabetes. RESULTS In a series of 12 illustrative cases, suboptimal control of blood glucose levels in patients with diabetes prompted further investigation. Assessment of C-peptide levels helped determine a precise diagnosis of type 1 or type 2 diabetes, information that was pivotal in choosing treatment options and improving the outcome. These examples show that the age of the patient at the time of diagnosis of diabetes does not necessarily indicate the type of diabetes that is present. CONCLUSION Clinicians should be aware of the importance of establishing whether patients have type 1 or type 2 diabetes mellitus and the implications of that distinction on the effectiveness of therapeutic strategies.
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