76
|
Baker KE, Wood LM, Whittaker M, Curtis MJ. Nupafant, a PAF-antagonist prototype for suppression of ventricular fibrillation without liability for QT prolongation? Br J Pharmacol 2006; 149:269-76. [PMID: 16921398 PMCID: PMC2014274 DOI: 10.1038/sj.bjp.0706846] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE PAF antagonists inhibit ischaemia-induced ventricular fibrillation (VF) in animals. However, unfavourable ancillary actions (on QT interval and coronary flow) have been reported with the PAF antagonist, BN-50739. If these are class actions, they would preclude development of PAF antagonists as novel anti-VF drugs. Our purpose was to examine this proposition using the hitherto untested PAF antagonist, nupafant. EXPERIMENTAL APPROACH Two rat heart preparations (Langendorff and 'dual coronary' perfusion) were used to assay nupafant's effects on ischaemia-induced VF, coronary flow and QT interval, and to test for the site-selectivity necessary if any effects on VF are caused by PAF antagonism. KEY RESULTS Global (whole-heart) delivery of 10 microM nupafant, reduced the incidence of ischaemia-induced VF and widened QT interval without affecting coronary flow. Importantly, lower concentrations (0.1 and 1 microM) had no effect on VF, yet widened QT almost identically to 10 microM nupafant. When nupafant was delivered selectively to (and entrapped within) the involved region it partially protected against VF (P<0.05). This occurred without change in QT interval. Selective nupafant delivery to the uninvolved region was without effect. CONCLUSIONS AND IMPLICATIONS Nupafant protects against ischaemia-induced VF primarily by site-selective actions in the ischaemic region but, unlike BN-50739, the effect is unrelated to its QT widening action, and is not compromised by any effect on coronary flow. This establishes proof of concept that VF suppression by PAF antagonism need not invariably be associated with QT prolongation or vasodilatation, justifying further development of this drug class.
Collapse
|
77
|
Marks IM, Kenwright M, McDonough M, Whittaker M, Mataix-Cols D. Saving clinicians' time by delegating routine aspects of therapy to a computer: a randomized controlled trial in phobia/panic disorder. Psychol Med 2004; 34:9-17. [PMID: 14971623 DOI: 10.1017/s003329170300878x] [Citation(s) in RCA: 174] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND The demand for time-consuming psychotherapy of phobia/panic exceeds the supply of trained therapists. Delegating routine therapy aspects to a computer might ease this problem. METHOD Ninety-three out-patients with phobia or panic disorder were randomized in a 2: 2 : 1 ratio to have self-exposure therapy guided either mainly by a stand-alone computer system (FearFighter) or entirely face-to-face by a clinician, or to have mainly computer-guided self-relaxation as a placebo. Both computer groups (FearFighter and relaxation) had brief back-up advice from a clinician. Primary outcome measures were self- and blind-assessor ratings of Main Problem and Goals, and Global Phobia. RESULTS Drop-outs occurred significantly more often in the two self-exposure groups (43% if mainly computer-guided, 24% if entirely clinician-guided) than with self-relaxation (6%); the difference between the two self-exposure groups was not significant. Even with all drop-outs included, the mainly computer-guided exposure group and the relaxation group had 73% less clinician time per patient than did the entirely clinician-guided exposure group. The two self-exposure groups had comparable improvement and satisfaction at post-treatment and at 1-month follow-up, while relaxation was ineffective. Mean improvement on the primary outcome measures (self- and assessor-rated) was 46% computer, 49% clinician, 9% relaxation at post-treatment (week 10) and 58% computer, 53% clinician and -4% relaxation at 1-month follow-up (week 14). Mean effect sizes on the primary outcome measures were 2.9 computer, 3.5 clinician and 0.5 relaxation at post-treatment; and 3.7 computer, 3.5 clinician and 0.5 relaxation at 1-month follow-up. The assessor did not rate patients at follow-up. CONCLUSIONS Despite its (non-significantly) higher dropout rate, self-exposure therapy for panic/ phobia cut clinician time per patient by 73% without losing efficacy when guided mainly by a computer rather than entirely by a clinician. The finding needs confirmation at a follow-up that is longer and includes a blind assessor. Self-relaxation had the highest rate of completers but was ineffective.
Collapse
|
78
|
Abstract
Through case studies of two women, this paper uses a taskonomy approach to analyze rural Vietnamese women's narratives of prevention, treatment and management of vaginal discharge to illustrate care seeking, health practice and the pragmatism of their action. The research is based upon ethnographic research undertaken by the author between 1995 and 1997 in a rural district in northern Vietnam. This exploration illustrates the complexities of women's rationalities and the web of influences upon their choices-the health seeking culture as practiced. The women's narratives are also placed within the broader context of gender, power and health systems that structure their decision making. The author discusses how social and economic resource factors influence the choices women make regarding when to begin treatment for vaginal discharge and where to seek care. She concludes that women use their understanding of the relationships between health, living conditions and diseases on a day-to-day basis and that the practice of managing vaginal discharge is mediated by concepts of body, self and the body politic in Vietnam.
Collapse
|
79
|
Pratt LM, Beckett RP, Davies SJ, Launchbury SB, Miller A, Spavold ZM, Todd RS, Whittaker M. Asymmetric synthesis of BB-3497--a potent peptide deformylase inhibitor. Bioorg Med Chem Lett 2001; 11:2585-8. [PMID: 11551755 DOI: 10.1016/s0960-894x(01)00509-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
By screening a library of metalloenzyme inhibitors, the N-formyl-hydroxylamine derivative BB-3497 was identified as a potent inhibitor of Escherichia coli peptide deformylase with antibacterial activity both in vitro and in vivo. The homochiral synthesis of BB-3497, involving a novel asymmetric Michael addition reaction is described.
Collapse
|
80
|
Patel R, Barton SE, Brown D, Cowan FM, Kinghorn GR, Munday PE, Scoular A, Timmins D, Whittaker M, Woolley P. European guideline for the management of genital herpes. Int J STD AIDS 2001; 12 Suppl 3:34-9. [PMID: 11589795 DOI: 10.1258/0956462011924092] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
81
|
Whittaker M, Floyd CD, Brown P, Gearing AJ. Design and therapeutic application of matrix metalloproteinase inhibitors. (Chem. Rev. 1999, 99, 2735-2776. Published on the web september 8, 1999). Chem Rev 2001; 101:2205-6. [PMID: 11749369 DOI: 10.1021/cr0100345] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
82
|
Clements JM, Beckett RP, Brown A, Catlin G, Lobell M, Palan S, Thomas W, Whittaker M, Wood S, Salama S, Baker PJ, Rodgers HF, Barynin V, Rice DW, Hunter MG. Antibiotic activity and characterization of BB-3497, a novel peptide deformylase inhibitor. Antimicrob Agents Chemother 2001; 45:563-70. [PMID: 11158755 PMCID: PMC90327 DOI: 10.1128/aac.45.2.563-570.2001] [Citation(s) in RCA: 165] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Peptide deformylase (PDF) is an essential bacterial metalloenzyme which deformylates the N-formylmethionine of newly synthesized polypeptides and as such represents a novel target for antibacterial chemotherapy. To identify novel PDF inhibitors, we screened a metalloenzyme inhibitor library and identified an N-formyl-hydroxylamine derivative, BB-3497, and a related natural hydroxamic acid antibiotic, actinonin, as potent and selective inhibitors of PDF. To elucidate the interactions that contribute to the binding affinity of these inhibitors, we determined the crystal structures of BB-3497 and actinonin bound to Escherichia coli PDF at resolutions of 2.1 and 1.75 A, respectively. In both complexes, the active-site metal atom was pentacoordinated by the side chains of Cys 90, His 132, and His 136 and the two oxygen atoms of N-formyl-hydroxylamine or hydroxamate. BB-3497 had activity against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis, and activity against some gram-negative bacteria. Time-kill analysis showed that the mode of action of BB-3497 was primarily bacteriostatic. The mechanism of resistance was via mutations within the formyltransferase gene, as previously described for actinonin. While actinonin and its derivatives have not been used clinically because of their poor pharmacokinetic properties, BB-3497 was shown to be orally bioavailable. A single oral dose of BB-3497 given 1 h after intraperitoneal injection of S. aureus Smith or methicillin-resistant S. aureus protected mice from infection with median effective doses of 8 and 14 mg/kg of body weight, respectively. These data validate PDF as a novel target for the design of a new generation of antibacterial agents.
Collapse
|
83
|
Whittaker M, Bergmann D, Arciero D, Hooper AB. Electron transfer during the oxidation of ammonia by the chemolithotrophic bacterium Nitrosomonas europaea. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1459:346-55. [PMID: 11004450 DOI: 10.1016/s0005-2728(00)00171-7] [Citation(s) in RCA: 139] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The combined action of ammonia monooxygenase, AMO, (NH(3)+2e(-)+O(2)-->NH(2)OH) and hydroxylamine oxidoreductase, HAO, (NH(2)OH+H(2)O-->HNO(2)+4e(-)+4H(+)) accounts for ammonia oxidation in Nitrosomonas europaea. Pathways for electrons from HAO to O(2), nitrite, NO, H(2)O(2) or AMO are reviewed and some recent advances described. The membrane cytochrome c(M)552 is proposed to participate in the path between HAO and ubiquinone. A bc(1) complex is shown to mediate between ubiquinol and the terminal oxidase and is shown to be downstream of HAO. A novel, red, low-potential, periplasmic copper protein, nitrosocyanin, is introduced. Possible mechanisms for the inhibition of ammonia oxidation in cells by protonophores are summarized. Genes for nitrite- and NO-reductase but not N(2)O or nitrate reductase are present in the genome of Nitrosomonas. Nitrite reductase is not repressed by growth on O(2); the flux of nitrite reduction is controlled at the substrate level.
Collapse
|
84
|
Pal B, Foxall M, Dysart T, Carey F, Whittaker M. How is gout managed in primary care? A review of current practice and proposed guidelines. Clin Rheumatol 2000; 19:21-5. [PMID: 10752494 DOI: 10.1007/s100670050005] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Twelve practices with a total list of 74,111 patients were audited; 429 patients were identified with a diagnosis of gout. A wide variation in various clinical and laboratory assessments was detected. Similar variations were also noted regarding dietary advice and medical treatment. Monitoring of patients was infrequent. As a result of this audit, guidelines are proposed to improve the diagnosis and management of gout in the community.
Collapse
|
85
|
Floyd CD, Leblanc C, Whittaker M. Combinatorial chemistry as a tool for drug discovery. PROGRESS IN MEDICINAL CHEMISTRY 2000; 36:91-168. [PMID: 10818672 DOI: 10.1016/s0079-6468(08)70046-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The question 'will combinatorial chemistry deliver real medicines' has been posed [96]. First it is important to realise that the chemical part of the drug discovery process cannot stand alone; the integration of synthesis and biological assays is fundamental to the combinatorial approach. The results presented in Tables 3.1 to 3.8 suggest that so far smaller directed combinatorial libraries have obtained equivalent results to those obtained previously from traditional medicinal chemistry analogue programs. Unfortunately, because of the long time it takes to develop pharmaceutical drugs there are no examples yet of marketed drugs discovered by combinatorial methods. There are interesting examples where active leads have been discovered from the screening of the same library against multiple targets (e.g. libraries 13, 39, 43, 66, 71 and 76). It is now possible to handle much larger libraries of non-oligomeric structures and the chemistry required for such applications is becoming available. Whether combinatorial approaches can also be adapted to deal with all the other requirements of a successful pharmaceutical (lack of toxicity, bioavailability etc.) is open to question but there are already examples such as cassette dosing [235-237]. However we can still be optimistic about the possibility of larger libraries producing avenues of investigation for the medicinal chemist to develop into real drugs. Combinatorial chemistry is an important tool for the medicinal chemist.
Collapse
|
86
|
Rice S, Lin AW, Safer D, Hart CL, Naber N, Carragher BO, Cain SM, Pechatnikova E, Wilson-Kubalek EM, Whittaker M, Pate E, Cooke R, Taylor EW, Milligan RA, Vale RD. A structural change in the kinesin motor protein that drives motility. Nature 1999; 402:778-84. [PMID: 10617199 DOI: 10.1038/45483] [Citation(s) in RCA: 570] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Kinesin motors power many motile processes by converting ATP energy into unidirectional motion along microtubules. The force-generating and enzymatic properties of conventional kinesin have been extensively studied; however, the structural basis of movement is unknown. Here we have detected and visualized a large conformational change of an approximately 15-amino-acid region (the neck linker) in kinesin using electron paramagnetic resonance, fluorescence resonance energy transfer, pre-steady state kinetics and cryo-electron microscopy. This region becomes immobilized and extended towards the microtubule 'plus' end when kinesin binds microtubules and ATP, and reverts to a more mobile conformation when gamma-phosphate is released after nucleotide hydrolysis. This conformational change explains both the direction of kinesin motion and processive movement by the kinesin dimer.
Collapse
|
87
|
Martin FM, Beckett RP, Bellamy CL, Courtney PF, Davies SJ, Drummond AH, Dodd R, Pratt LM, Patel SR, Ricketts ML, Todd RS, Tuffnell AR, Ward JW, Whittaker M. The synthesis and biological evaluation of non-peptidic matrix metalloproteinase inhibitors. Bioorg Med Chem Lett 1999; 9:2887-92. [PMID: 10522712 DOI: 10.1016/s0960-894x(99)00494-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Novel sulfonamide matrix metalloproteinase inhibitors of general formula (9) were synthesised by a route involving a stereoselective conjugate addition reaction. Enzyme selectivity was found to be dependant on the nature of the sulfonamide substituents. Compounds (9f, 9q) are potent selective collagenase inhibitors with good oral bioavailability.
Collapse
|
88
|
Hawe JA, Clayton R, Phillips G, Whittaker M, Kucukmetin A, Garry R. Laparoscopic-assisted Doderlein hysterectomy: retrospective analysis of 300 consecutive cases. BRITISH JOURNAL OF OBSTETRICS AND GYNAECOLOGY 1999; 106:1083-8. [PMID: 10519436 DOI: 10.1111/j.1471-0528.1999.tb08118.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To assess the clinical outcomes of the Doderlein laparoscopic-assisted hysterectomy. DESIGN A retrospective study. SETTING Women's Endoscopic Laser Foundation at South Cleveland Hospital, Middlesbrough and St James's University Hospital, Leeds. POPULATION Three hundred consecutive women who had a laparoscopic-assisted Doderlein hysterectomy. METHODS Patients were identified from the laparoscopic hysterectomy theatre log at both sites. Case notes were requested and examined. MAIN OUTCOME MEASURES Operative time, uterine weight, associated pelvic pathology, blood loss, hospital stay, intra-operative and post-operative complications. RESULTS The operations were performed by eight different surgeons, seven of whom were laparoscopic trainees. The mean operating time was 102 minutes (SD 30). Additional surgery including unilateral or bilateral salpingo-oophorectomy, was carried out in 247 patients (82%). The mean uterine weight was 140 g (SD 74). One hundred and thirty-two women (44%) had a normal pelvis at hysterectomy. The mean drop in haemoglobin and haematocrit was 1.46 g (SD 0.95) and 4.4% (SD 2.8), respectively. The overall complication rate was 18%, of which 6.2% were classed as major. The major complications included four cystotomies, five unscheduled laparotomies, seven post-operative blood transfusions, one pulmonary embolus and two re-operations (within six weeks). The mean hospital stay was three days. CONCLUSIONS Laparoscopic-assisted Doderlein hysterectomy is an alternative to standard laparoscopic hysterectomy techniques. It has the advantage of being easy to learn and is associated with low complication rates, compared with other laparoscopic and traditional techniques for hysterectomy.
Collapse
|
89
|
Whittaker M, Floyd CD, Brown P, Gearing AJ. Design and therapeutic application of matrix metalloproteinase inhibitors. Chem Rev 1999; 99:2735-76. [PMID: 11749499 DOI: 10.1021/cr9804543] [Citation(s) in RCA: 755] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
90
|
Drummond AH, Beckett P, Brown PD, Bone EA, Davidson AH, Galloway WA, Gearing AJ, Huxley P, Laber D, McCourt M, Whittaker M, Wood LM, Wright A. Preclinical and clinical studies of MMP inhibitors in cancer. Ann N Y Acad Sci 1999; 878:228-35. [PMID: 10415734 DOI: 10.1111/j.1749-6632.1999.tb07688.x] [Citation(s) in RCA: 168] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The role of matrix metalloproteinases in tumor angiogenesis and growth is now well recognized for models of both human and animal cancer. Clinical studies currently under way with the prototype matrix metalloproteinase inhibitor, marimastat, will establish whether inhibitors of these enzymes are of benefit in the treatment of different types of human cancer. On chronic therapy in humans, marimastat induces a reversible tendinitis that can also be detected in certain animal species. This paper compares the ability of broad-spectrum and various types of selective matrix metalloproteinase inhibitors to induce tendinitis and to exhibit anticancer effects in an animal cancer model. Under conditions in which both systemic exposure and inhibitor potency are controlled, selective inhibitors are less pro-tendinitic, but are weaker anticancer agents than broad-spectrum agents such as marimastat. The clinical relevance of these findings is discussed.
Collapse
|
91
|
Wieler M, Stein RB, Ladouceur M, Whittaker M, Smith AW, Naaman S, Barbeau H, Bugaresti J, Aimone E. Multicenter evaluation of electrical stimulation systems for walking. Arch Phys Med Rehabil 1999; 80:495-500. [PMID: 10326910 DOI: 10.1016/s0003-9993(99)90188-0] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To test the long-term benefits of several noninvasive systems for functional electrical stimulation (FES) during walking. DESIGN Forty subjects (average years since injury, 5.4) were studied in four centers for an average time of 1 year. Gait parameters were tested for all subjects with and without FES. Thus, subjects served as their own controls, since the specific effect of using FES could be separated from improvements resulting from other factors (e.g., training). SETTING Subjects used the devices in the community, but were tested in a university or hospital setting. PATIENTS Subjects with spinal cord injury (n = 31) were compared to subjects with cerebral damage (n = 9). MAIN OUTCOME MEASURES Gait parameters (speed, cycle time, stride length). Acceptance was studied by means of a questionnaire. RESULTS Some initial improvement in walking speed (average increase of >20%) occurred, and continuing gains were seen (average total improvement, 45%). The largest relative gains were seen in the slowest walkers (speeds of <0.3 m/sec). Acceptance of the FES systems was good and improved systems have been developed using feedback from the subjects. CONCLUSIONS Based on the improvements in speed and the acceptance of these FES systems, a greatly increased role for FES in treating gait disorders is suggested.
Collapse
|
92
|
Pollard SJ, Whittaker M, Risden GC. The fate of heavy oil wastes in soil microcosms. I: A performance assessment of biotransformation indices. THE SCIENCE OF THE TOTAL ENVIRONMENT 1999; 226:1-22. [PMID: 10077871 DOI: 10.1016/s0048-9697(98)00346-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A controlled soil microcosm study was used to evaluate the performance of selected oil biotransformation indices using samples of Nigerian crude, a blended ballast oil and No. 6 fuel oil. Biotic losses were demonstrated through loss of solvent extractable matter (SEM) and changes in class fraction distribution in weathered soil extracts relative to sterilised controls. GC-EI MS peak identification and quantification was achieved for selected (sigma) n-alkanes, the isoprenoid alkanes norpristane (iC18), pristane (iC19) and phytane (iC20), combined mono-substituted (1-, 2-, 3- and 9-) methylphenanthrenes (sigma methylphenanthrenes), combined dimethylphenanthrenes (sigma dimethylphenanthrenes) and the hopane isomers 17 alpha(H)21 beta(H)-hopane and 17 alpha(H)21 beta(H)-30-norhopane. The [sigma n-alkanes:17 alpha(H)21 beta(H)-hopane] index was most sensitive to oil biotransformation and most accurately reflected depletion of oil from contaminated soils in this study. This index was found to be the most reliable for the No. 6 fuel oil saturates, dropping from 81.9 to 18.1 over the course of the 256-day microcosm study. In terms of sensitivity, and taking into account the results of an ANOVA analysis, the biotransformation indices most sensitive to oil biotransformation were (in order of decreasing sensitivity): [sigma C14-28:17 alpha(H)21 beta(H)-hopane] >> [sigma C14-28:sigma dimethylphenanthrenes] > [C18:phytane].
Collapse
|
93
|
Whittaker M, Pollard SJ, Risden G. The fate of heavy oil wastes in soil microcosms. II: A performance assessment of source correlation indices. THE SCIENCE OF THE TOTAL ENVIRONMENT 1999; 226:23-34. [PMID: 10077872 DOI: 10.1016/s0048-9697(98)00358-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Chemical fingerprinting is commonly undertaken to assist in the resolution of multi-party liability disputes, particularly when contaminants have migrated beyond property boundaries, in litigation-driven environmental assessments related to oil spills, and in assessing potential environmental impacts following releases of petroleum products into the environment. In this paper, we present data relating to the performance of source correlation indices for selected heavy oils over the course of a 9-month microcosm study. The results obtained in this study demonstrated that hopane pair indices varied little in magnitude, and may therefore be considered reliable source correlation indices. Over the course of the 9-month microcosm study [17 alpha(H)21 beta(H)-norhopane: 17 alpha(H)21 beta(H)-hopane] exhibited mean values of 0.7 +/- 0.1 for a heavy ballast oil, and mean values that varied between 0.6 and 0.7 (+/- 0.05) for a crude oil. Similarly [(17 alpha(H)21 beta(H)-homohopane (22S): 17 alpha(H)21 beta(H)-homohopane (22R)] gave a mean value of 1.3 (precisions less than 0.05) and [17 alpha(H)21 beta(H)-bishomohopane: 17 alpha(H)21 beta(H)-methylhopane] varied between 1.3 and 1.6 (precision up to 0.1) for the same crude oil. These source correlation indices may be used to support a correlation between fresh and weathered oil samples for source identification purposes involving heavy and crude oil contamination of the terrestrial environment.
Collapse
|
94
|
Abstract
A high-resolution model of the microtubule has been obtained by docking the crystal structure of tubulin into a 20 A map of the microtubule. The excellent fit indicates the similarity of the tubulin conformation in both polymers and defines the orientation of the tubulin structure within the microtubule. Long C-terminal helices form the crest on the outside of the protofilament, while long loops define the microtubule lumen. The exchangeable nucleotide in beta-tubulin is exposed at the plus end of the microtubule, while the proposed catalytic residue in alpha-tubulin is exposed at the minus end. Extensive longitudinal interfaces between monomers have polar and hydrophobic components. At the lateral contacts, a nucleotide-sensitive helix interacts with a loop that contributes to the binding site of taxol in beta-tubulin.
Collapse
|
95
|
Ammori BJ, Madan M, Gopichandran TD, Price JJ, Whittaker M, Ausobsky JR, Antrum RM. Ultrasound-guided unilateral neck exploration for sporadic primary hyperparathyroidism: is it worthwhile? Ann R Coll Surg Engl 1998; 80:433-7. [PMID: 10209415 PMCID: PMC2503160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
The role of preoperative localisation tests before initial neck exploration for primary hyperparathyroidism (PHP) remains controversial, as does the optimal surgical approach. We report our experience with preoperative ultrasound (US) and the operative management of sporadic PHP between 1990 and 1995. Preoperative US was carried out by an experienced radiologist. Three surgeons adopted a policy of 'selective' US-guided unilateral neck exploration (UNE); the fourth surgeon performed routine bilateral neck exploration (BNE). There were 72 patients: 26 men and 46 women, with a mean age of 57.4 +/- 12.5 years (range 21-80 years). All patients underwent initial neck exploration for 'sporadic' PHP, of whom 63 had preoperative US. This was positive in 52 patients; 27 of whom underwent a UNE, 23 had a BNE, and two patients had a UNE converted to a BNE. Patients with 'negative' US (n = 11), and those receiving no preoperative localisation test (n = 90) underwent a BNE. The sensitivity, specificity and accuracy of US were 80% (52/65), 100% (61/61), and 90% (113/126), respectively. Comparable success rates were achieved (BNE: 97% (33/34) vs UNE: 93% (27/29), P < 0.05), with very low morbidity. Failures with the scan-guided UNE were caused by missed contralateral adenomas. An experienced radiologist and a low incidence of multiglandular disease (MGD) are essential prerequisites for the scan-guided unilateral approach. An experienced surgeon, on the other hand, is the only prerequisite for the 'gold standard' bilateral approach.
Collapse
|
96
|
Whittaker M, Brown P. Recent advances in matrix metalloproteinase inhibitor research and development. CURRENT OPINION IN DRUG DISCOVERY & DEVELOPMENT 1998; 1:157-164. [PMID: 19649815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
|
97
|
Pratt LM, Beckett RP, Bellamy CL, Corkill DJ, Cossins J, Courtney PF, Davies SJ, Davidson AH, Drummond AH, Helfrich K, Lewis CN, Mangan M, Martin FM, Miller K, Nayee P, Ricketts ML, Thomas W, Todd RS, Whittaker M. The synthesis of novel matrix metalloproteinase inhibitors employing the Ireland-Claisen rearrangement. Bioorg Med Chem Lett 1998; 8:1359-64. [PMID: 9871766 DOI: 10.1016/s0960-894x(98)00218-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Matrix metalloproteinase inhibitors of general formula (1) were synthesised by a route involving an Ireland-Claisen rearrangement which enables systematic modification of the substituent alpha to the hydroxamic acid. An analogue (12c) possessing an alpha-cyclopentyl group is a potent broad spectrum inhibitor that displays high and sustained blood levels following oral dosing in both the rat and marmoset ex-vivo bioassays. This compound and analogues are also potent inhibitors of TNF alpha release.
Collapse
|
98
|
Abstract
There continues to be considerable effort towards the construction of compound libraries targeted for the inhibition of protease enzymes. New tag-encoding methods for library deconvolution have been applied to this problem and there has been particular interest in novel solid-phase linkers for the introduction of key pharmacophore groups required for protease inhibition. Recent reports have tended to focus on nonpeptidic libraries, and, notably, structure-based design methods are now being applied to direct library design.
Collapse
|
99
|
Clarke L, Whittaker M. Self-mutilation: culture, contexts and nursing responses. J Clin Nurs 1998; 7:129-37. [PMID: 9582763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Few papers address the issue of deliberate self-mutilation other than from clinical perspectives. This paper advocates a user-perspective and discusses some of the issues which might attend such a change. The occurrence of self-mutilation is placed within a cultural framework so as to enlarge the debate beyond the confines of medical/nursing responses. It is suggested that nurses abrogate their attachment to such responses and embrace more collaborative approaches to care. In particular, nurses are asked to review their (moral) responses to self-mutilation, an activity which, too often, has been responded to with scorn and derision.
Collapse
|
100
|
Koenig MA, Hossain MB, Whittaker M. The influence of quality of care upon contraceptive use in rural Bangladesh. Stud Fam Plann 1997; 28:278-89. [PMID: 9431649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Efforts to develop quantitative indicators of quality of care for family planning services, and to evaluate its role in contraceptive behavior, remain at an early stage. The present study, based upon an analysis of prospective data from a sample of 7,800 reproductive-aged rural Bangladeshi women, provides empirical evidence on the importance of quality of care for contraceptive practice. The results demonstrate that the perceptions of women regarding the quality of field-worker care were significantly related to the probability of subsequent adoption of a family planning method. Women who were not using a method and who scored high on an index of perceived quality of care were 27 percent more likely to adopt a method subsequently, compared with women with a low score. Effects were even more pronounced for contraceptive continuation; high quality of care was associated with a 72 percent greater likelihood of continued use of any method of contraception.
Collapse
|