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Rodgers M, Hodges R, Hawkins J, Hollingworth W, Duffy S, McKibbin M, Mansfield M, Harbord R, Sterne J, Glasziou P, Whiting P, Westwood M. Colour vision testing for diabetic retinopathy: a systematic review of diagnostic accuracy and economic evaluation. Health Technol Assess 2010; 13:1-160. [PMID: 20003824 DOI: 10.3310/hta13600] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To determine the diagnostic performance and cost-effectiveness of colour vision testing (CVT) to identify and monitor the progression of diabetic retinopathy (DR). DATA SOURCES Major electronic databases including MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Database of Systematic Reviews were searched from inception to September 2008. REVIEW METHODS A systematic review of the evidence was carried out according to standard methods. An online survey of National Screening Programme for Diabetic Retinopathy (NSPDR) clinical leads and programme managers assessed the diagnostic tools used routinely by local centres and their views on future research priorities. A decision tree and Markov model was developed to estimate the incremental costs and effects of adding CVT to the current NSPDR. RESULTS In total, 25 studies on CVT met the inclusion criteria for the review, including 18 presenting 2 x 2 diagnostic accuracy data. The quality of studies and reporting was generally poor. Automated or computerised CVTs reported variable sensitivities (63-97%) and specificities (71-95%). One study reported good diagnostic accuracy estimates for computerised CVT plus retinal photography for detection of sight-threatening DR, but it included few cases of retinopathy in total. Results for pseudoisochromatic plates, anomaloscopes and colour arrangement tests were largely inadequate for DR screening, with Youden indices (sensitivity + specificity - 100%) close to zero. No studies were located that addressed patient preferences relating to CVT for DR. Retinal photography is universally employed as the primary method for retinal screening by centres responding to the online survey; none used CVT. The review of the economic evaluation literature found no previous studies describing the cost and effects of any type of CVT. Our economic evaluation suggested that adding CVT to the current national screening programme could be cost-effective if it adequately increases sensitivity and is relatively inexpensive. The deterministic base-case analysis indicated that the cost per quality-adjusted life-year gained may be 6364 pounds and 12,432 pounds for type 1 and type 2 diabetes respectively. However, probabilistic sensitivity analysis highlighted the substantial probability that CVT is not diagnostically accurate enough to be either an effective or a cost-effective addition to current screening methods. The results of the economic model should be treated with caution as the model is based on only one small study. CONCLUSIONS There is insufficient evidence to support the use of CVT alone, or in combination with retinal photography, as a method for screening for retinopathy in patients with diabetes. Better quality diagnostic accuracy studies directly comparing the incremental value of CVT in addition to retinal photography are needed before drawing conclusions on cost-effectiveness. The most frequently cited preference for future research was the use of optical coherence tomography for the detection of clinically significant macular oedema.
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Shapiro M, Duca KA, Lee K, Delgado-Eckert E, Hawkins J, Jarrah AS, Laubenbacher R, Polys NF, Hadinoto V, Thorley-Lawson DA. A virtual look at Epstein-Barr virus infection: simulation mechanism. J Theor Biol 2008; 252:633-48. [PMID: 18371986 DOI: 10.1016/j.jtbi.2008.01.032] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Revised: 01/09/2008] [Accepted: 01/28/2008] [Indexed: 10/22/2022]
Abstract
Epstein-Barr virus (EBV) is an important human pathogen that establishes a life-long persistent infection and for which no precise animal model exists. In this paper, we describe in detail an agent-based model and computer simulation of EBV infection. Agents representing EBV and sets of B and T lymphocytes move and interact on a three-dimensional grid approximating Waldeyer's ring, together with abstract compartments for lymph and blood. The simulation allows us to explore the development and resolution of virtual infections in a manner not possible in actual human experiments. Specifically, we identify parameters capable of inducing clearance, persistent infection, or death.
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Hawkins J, Wells J. How infrastructure procurement can enhance social development. PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-MANAGEMENT PROCUREMENT AND LAW 2007. [DOI: 10.1680/mpal.2007.160.1.33] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This paper reports the findings of a study by Engineers Against Poverty and the Institution of Civil Engineers into the factors in infrastructure procurement that are currently inhibiting the achievement of social development objectives. The paper explores the impact/performance of the asset and the service it delivers (the product), and the opportunities during the project's construction and operation (the process). The study adopted a very broad definition of ‘procurement’ to embrace all stages from project identification to the final monitoring, enforcement and evaluation. Methods included reviews of procurement documentation and practice in four case-study countries (India, Indonesia, Kenya and Nigeria), round-table discussions and in-depth interviews with stakeholders. This yielded a long list of inhibiting factors but also some encouraging efforts at reform. The paper concludes that procurement procedures and contract agreement have the potential to promote social objectives. However, the objectives should be clearly identified in the project design; the budget and procurement strategy have to be appropriate; and implementation must be monitored and enforced.
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Hawkins J. A reply. Anaesthesia 2004. [DOI: 10.1111/j.1365-2044.2004.3826b.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Li J, Hawkins J. A system for evaluating inpatient care cost-efficiency in a hospital. Stud Health Technol Inform 2002; 84:1171-4. [PMID: 11604914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The cost-efficiency evaluation is one important aspect in the health care organization performance assessment. This paper introduces the ratio of exact cost to Relative Intensity Weights, cost per case weight, as one indicator. A statistical approach for cost-efficiency analyses is presented in this paper. The analyses would be done at the population level and patient level. The linkage between population and individual patients provides the capability to review the distributions of several cost-efficiency measures and to do further studies, including factor adjustment. A well established health care data warehouse is to accomplish a timely and evaluation of the cost-efficiency in hospital.
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Geanellos R, Fry A, Pearce H, Williams J, Hawkins J, Manning E, Cowell K. 'The experience of community mental health case management provided from an acute in-patient psychiatric unit'. THE INTERNATIONAL JOURNAL OF PSYCHIATRIC NURSING RESEARCH 2001; 7:815-32. [PMID: 11915388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
In Australia, case management is the cornerstone of mental health service delivery for seriously ill clients living in the community. In this study, case management was provided from an acute, inpatient psychiatric unit; a model thought to be unique. Findings from this qualitative study explicated the experience of case management from client and case manager (CM) perspectives. They note the nature, purpose, processes and outcomes of case management within that context. Findings were positive, suggesting clients and CM's develop a therapeutic alliance through which interventions are implemented and which result in clients experiencing personal (re) integration and enhanced well-being. These findings are discussed and they suggest an alternative model of service delivery well regarded by both clients and CM's.
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Hawkins J. Addressing the shortage of radiologists. RADIOLOGY MANAGEMENT 2001; 23:26-8. [PMID: 11499079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
In a survey of 254 hospital radiology departments conducted last year, Dallas-based U.S. Radiology Partners (USRP), a radiology management firm, found that 45 percent of hospitals are understaffed in radiology. Fifty-six percent of hospital radiology department heads surveyed by USRP indicated that staffing shortages were diminishing the quality of care their departments are able to provide. Moreover, staffing shortages are occurring at a time when radiology volume generally is increasing. There are various underlying reasons why the supply of radiologists and other physicians is insufficient to meet demand in many areas, including institutional misdiagnosis, graduate medical education, patient preferences, the economy, restrictions on international medical graduates, practice patterns, patient and physician demographics and new technology. Given current physician supply and demand trends, a strategic radiology staffing plan is needed. Such a plan would include the following elements: retention, candidate parameters, contracts and incentives, sourcing, screening, interviewing, responsiveness and decisiveness.
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Hawkins J, Marcy A. Characterization of Itk tyrosine kinase: contribution of noncatalytic domains to enzymatic activity. Protein Expr Purif 2001; 22:211-9. [PMID: 11437596 DOI: 10.1006/prep.2001.1447] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Itk is a Tec family tyrosine kinase found in T cells that is activated upon ligation of the T cell receptor (TCR/CD3), CD2, or CD28. Itk contains five domains in addition to the catalytic domain: pleckstrin homology, Tec homology which contains a proline-rich region, Src homology 3, and Src homology 2. To provide a basis for understanding the contribution of these various domains to catalysis, recombinant Itk was purified and its substrate specificity determined by steady-state kinetic methods. Measurements of the rates of phosphorylation of various protein substrates, including Src associated in mitosis 68K protein (SAM68), CD28, linker for activation of T cells, and CD3 zeta, at a fixed concentration indicated that SAM68 was phosphorylated most rapidly. Wild-type Itk and three Itk mutants were characterized by comparing their activity (k(cat)) using the SAM68 substrate. A deletion mutant removing the pleckstrin homology domain and part of the Tec homology domain (Itk(Delta152)) had approximately 10-fold less activity than wild type, a mutant with an altered proline-rich domain (P158A,P159A) had a more dramatic 100-fold loss of activity, and the catalytic domain alone was essentially inactive. Itk(Delta152) had K(m) values for ATP and SAM68 nearly identical to those of the wild-type enzyme, while Itk(P158A,P159A) had approximately 3-fold higher K(m) values for each substrate. SAM68 phosphorylation by the wild-type and mutant enzymes in the presence of several tyrosine kinase inhibitors were compared using a homogeneous time-resolved fluorescence assay. Both the Itk(Delta152) deletion mutant and the Itk(P158A,P159A) mutant had IC(50) values similar to those of the wild-type enzyme for staurosporine, PP1, and damnacanthal. These comparisons, taken together with the similar K(m) values for ATP and SAM68 substrate between the wild-type and the mutant enzymes, indicate that the amino acids in the N-terminal 152 residues and proline-rich domains enhance catalysis by affecting turnover rate rather than substrate binding.
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Haggerty LA, Kelly U, Hawkins J, Pearce C, Kearney MH. Pregnant women's perceptions of abuse. J Obstet Gynecol Neonatal Nurs 2001; 30:283-90. [PMID: 11383951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
OBJECTIVE To determine whether pregnant women's perceptions of abuse severity and danger, and their ability to control the abuse, are significantly correlated with the acts of abuse they experience, and to find out whether relationships exist among women's appraisals of abuse severity, danger, and their perceived ability to stop the abuse. DESIGN A correlational design was used to compare the abusive acts experienced by the women and their perceptions of that abuse. SETTING Nine prenatal clinics in urban areas of the northeastern United States. PARTICIPANTS Sixty-one ethnically diverse, pregnant abused women were interviewed. MAIN OUTCOME MEASURE Pearson's product-moment correlations were used to examine relationships between abusive experiences and women's perceptions of abuse. RESULTS Women's perceptions of abuse severity were modestly correlated with threatened (r = .25) and actual violence (r = .36). Perceptions of abuse severity and danger were correlated (r = .41). CONCLUSIONS Women's beliefs about abuse severity, danger, and their ability to control abuse cannot be fully comprehended by exploring the discrete acts they experience. Further research is needed to identify additional factors that influence those beliefs.
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Hawkins J. A new cohesive short-stretch bandage and its application. BRITISH JOURNAL OF NURSING (MARK ALLEN PUBLISHING) 2001; 10:249-53. [PMID: 12170650 DOI: 10.12968/bjon.2001.10.4.5373] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/01/2001] [Indexed: 11/11/2022]
Abstract
The undisputed optimum treatment for venous leg ulcers is compression therapy, where an external appliance (multilayer, short-stretch bandaging and compression hosiery) promotes venous return through graduated compression of the tissues and capillaries. However, this is not always acceptable to the patient, particularly when the patient's social life is affected with malodour and pain associated with venous leg ulcers, thereby reducing quality of life. There is a psychosocial consideration when the bandaging system is bulky, hot and difficulty is found with the fitting of shoes. An alternative and clinically effective solution is essential if the wound is to heal. In this case study, the patient was provided with a cohesive and short-stretch compression bandage (Actico), which allowed her to continue her social life while effectively treating her ulcer.
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Li J, Hawkins J. A system for evaluating inpatient care cost-efficiency in hospital. Proc AMIA Symp 2001:369-72. [PMID: 11825212 PMCID: PMC2243448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
The cost-efficiency evaluation is one important aspect in the health care organization performance assessment. This paper introduces the ratio of exact cost to Relative Intensity Weights, cost per case weight, as one indicator. A statistical approach for cost-efficiency analyses is presented in this paper. The analyses would be done at the population level and patient level. The linkage between population and individual patients provides the capability to review the distributions of several cost-efficiency measures and to do further studies, including factor adjustment. A well established health care data warehouse is to accomplish a timely and evaluation of the cost-efficiency in hospital.
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Hawkins J, Zheng S, Frantz B, LoGrasso P. p38 map kinase substrate specificity differs greatly for protein and peptide substrates. Arch Biochem Biophys 2000; 382:310-3. [PMID: 11068883 DOI: 10.1006/abbi.2000.2005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Chaudhry PA, Mishima T, Sharov VG, Hawkins J, Alferness C, Paone G, Sabbah HN. Passive epicardial containment prevents ventricular remodeling in heart failure. Ann Thorac Surg 2000; 70:1275-80. [PMID: 11081885 DOI: 10.1016/s0003-4975(00)01755-0] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND We examined the effects of passive containment of the cardiac ventricles with a surgically placed epicardial prosthetic wrap on indexes of left ventricular (LV) remodeling in dogs with heart failure. METHODS Heart failure (LV ejection fraction 30% to 40%) was produced in 12 dogs by intracoronary microembolization. Six dogs underwent mid-sternotomy and pericardiotomy with placement of a preformed-knitted polyester device (Acorn Cardiac Support Device [CSD], Acorn Cardiovascular, Inc, St. Paul, MN) snugly around the ventricles and anchored to the atrioventricular groove. Six dogs did not undergo surgery and served as controls. Dogs were followed for 3 months prior to sacrifice. RESULTS In controls, LV end-diastolic volume increased after 3 months (67 +/- 12 versus 83 +/- 8 ml; p = 0.04), while in CSD-treated dogs, it decreased (68 +/- 10 versus 61 +/- 10 ml; p = 0.002). CSD-containment of LV size was associated with increased LV systolic fractional area of shortening, while in controls, fractional area of shortening decreased. CSD-treated dogs also showed amelioration of myocyte hypertrophy and attenuation of interstitial fibrosis compared to controls. CONCLUSIONS In dogs with heart failure, passive epicardial containment of the ventricles with the Acorn CSD ameliorates LV remodeling and improves LV systolic function.
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Hawkins J. Midwives make a difference ... but who knows? THE PRACTISING MIDWIFE 2000; 3:4-5. [PMID: 12026439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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Abstract
Investigators encounter many legal and ethical issues when they conduct research on partner abuse. Balancing abused women's rights to privacy with legally mandated reporting requirements involves considerable thought and planning. Failure to protect participants may result in escalation of abuse as well as loss of children to protective services. Various perspectives on maintaining participant privacy while conforming to legal mandates to report child abuse, homicidality, and suicidality are discussed. The role of confidentiality certificates in providing legal immunity for researchers and the method of obtaining the certificates are presented. In addition, the authors describe the strategies for participant protection that are implemented in a federally funded study of abuse, women's self-care, and pregnancy outcomes. The decision to clearly and specifically inform abused women of the limits of confidentiality allows participants to make informed decisions about disclosures, but may result in diminished recruitment.
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Ward RV, Jennings KH, Jepras R, Neville W, Owen DE, Hawkins J, Christie G, Davis JB, George A, Karran EH, Howlett DR. Fractionation and characterization of oligomeric, protofibrillar and fibrillar forms of beta-amyloid peptide. Biochem J 2000; 348 Pt 1:137-44. [PMID: 10794724 PMCID: PMC1221046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The beta-amyloid (Abeta) peptide, a major component of senile plaques in Alzheimer's disease brain, has been shown previously to undergo a process of polymerization to produce neurotoxic forms of amyloid. Recent literature has attempted to define precisely the form of Abeta responsible for its neurodegenerative properties. In the present study we describe a novel density-gradient centrifugation method for the isolation and characterization of structurally distinct polymerized forms of Abeta peptide. Fractions containing protofibrils, fibrils, sheet structures and low molecular mass oligomers were prepared. The fractionated forms of Abeta were characterized structurally by transmission electron microscopy. The effects on cell viability of these fractions was determined in the B12 neuronal cell line and hippocampal neurons. Marked effects on cell viability in the cells were found to correspond to the presence of protofibrillar and fibrillar structures, but not to monomeric peptide or sheet-like structures of polymerized Abeta. Biological activity correlated with a positive reaction in an immunoassay that specifically detects protofibrillar and fibrillar Abeta; those fractions that were immunoassay negative had no effect on cell viability. These data suggest that the effect of Abeta on cell viability is not confined to a single conformational form but that both fibrillar and protofibrillar species have the potential to be active in this assay.
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See A, Kron T, Johansen J, Hamilton C, Bydder SA, Hawkins J, Roff M, Denham JW. Decision-making models in the analysis of portal films: a clinical pilot study. AUSTRALASIAN RADIOLOGY 2000; 44:72-83. [PMID: 10761263 DOI: 10.1046/j.1440-1673.2000.00775.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Portal films continue to play an important role in the verification of radiotherapy treatment. There is still some discussion, however, as to what action should be taken after a port film has shown a radiation field deviation from the prescribed volume. It was the aim of the present pilot study to investigate the performance of three decision-making models ('Amsterdam', 'Quebec' and 'Newcastle') and an expert panel basing their decision on intuition rather than formal rules after portal film acquisition in a clinical setting. Portal films were acquired on every day during the first week of treatment for five head and neck and five prostate cancer patients (diagnostic phase). If required, the field position was modified according to our normal practice following the recommendation of the expert panel. In order to analyse the results of the models, however, additional port films were taken in the following 3 treatment weeks with the patient moved as required by the different models (intervention phase). The portal films were taken over 4 consecutive days, positioning the patient according to each of the different models on one day each. None of the models diagnosed a field misplacement in the head and neck patients, while the 'Amsterdam' and 'Quebec' models predicted a move in one prostate patient. The 'Newcastle' model, which is based on Hotelling's T2 statistic, proved to be more sensitive and diagnosed a systematic displacement for three prostate patients. The intervention phase confirmed the diagnosis of the model, even if the three portal films taken with the patient position adjusted as required by the model proved to be insufficient to demonstrate an improvement. The 'Newcastle' model does not rely on assumptions about the random movement of patients and requires five portal films before a decision can be reached. This approach lends itself well to incorporation into electronic portal imaging 'packages', where repeated image acquisitions present no logistical difficulty.
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Hawkins J, Romero V. Practical ethics. How much to tell a recruit. HOSPITALS & HEALTH NETWORKS 2000; 74:24. [PMID: 11393189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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Cascio MG, Gaiser RR, Camann WR, Venkateswaran P, Hawkins J, McCarthy D. Comparative evaluation of four different infusion rates of ropivacaine (2 mg/mL) for epidural labor analgesia. Reg Anesth Pain Med 1998; 23:548-53. [PMID: 9840848 DOI: 10.1016/s1098-7339(98)90079-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND OBJECTIVES Previous studies have reported comparable efficacy for ropivacaine and bupivacaine when used for labor analgesia at concentrations of 2.5 mg/mL. In this multicenter study, we assessed ropivacaine at the commercially available concentration of 2 mg/mL (0.2%) for labor pain management. METHODS After Institutional Review Board approval and informed consent, 128 women at term were randomly assigned to receive ropivacaine at one of the four infusion rates via a lumbar epidural catheter. Analgesia was initiated with a 5-mL test dose, followed by injections of 5-15 mL of 2 mg/mL ropivacaine. The continuous infusion was then started at 4, 6, 8, or 10 rmL/hour. Rescue analgesia was provided with 5-mL "top-up" injections as necessary to provide maternal comfort. Pain relief was assessed by using a visual analog pain scale (VAPS) and motor block was assessed by using a modified Bromage scale. RESULTS All infusion regimens effectively decreased VAPS, and most patients in all groups had minimal or no motor block at the end of the first stage of labor. Mean total number of the top-up injections required per patient were 3, 2, 1.5, and 1.4, respectively, in the 4, 6, 8, and 10-mL/hour groups (P < .05, 4 mL/hour vs. all other groups). Despite receiving more total bolus dosages, the 4-mL/hour group had less motor block in the lower extremities (P < .05). Apgar scores and neurological adaptive capacity scores were similar for all groups. CONCLUSIONS The 2 mg/mL of ropivacaine produces satisfactory labor analgesia at epidural infusion rates of 4, 6, 8, and 10 mL/hour, provided supplemental bolus dosages are available. Clinically, a rate of 6 mL/hour may be the lowest effective rate that provides the best combination of pain relief, motor block, and rebolusing, although rates of 8 and 10 mL/hour produced similar results.
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Bromidge SM, Brown F, Cassidy F, Clark MS, Dabbs S, Hadley MS, Hawkins J, Loudon JM, Naylor CB, Orlek BS, Riley GJ. Design of [R-(Z)]-(+)-alpha-(methoxyimino)-1-azabicyclo[2.2.2]octane-3-acetonitri le (SB 202026), a functionally selective azabicyclic muscarinic M1 agonist incorporating the N-methoxy imidoyl nitrile group as a novel ester bioisostere. J Med Chem 1997; 40:4265-80. [PMID: 9435896 DOI: 10.1021/jm9702903] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Loss of cholinergic function is believed to be implicated in the cognitive decline associated with senile dementia of the Alzheimer type (SDAT). The disease is characterized by progressive loss of muscarinic receptors located on nerve terminals while postsynaptic muscarinic M1 receptors appear to remain largely intact. Muscarinic agonists acting directly on postsynaptic receptors offer the prospect of countering the cholinergic deficit in SDAT. This study describes a novel series of azabicyclic muscarinic agonists, which incorporate an oxime ether or modified oxime ether group as an ester bioisostere. Modification of the oxime ether function by the introduction of electron withdrawing groups led to the finding that the (Z)-N-methoxy imidoyl nitrile group serves as a stable methyl ester bioisostere. This culminated in the discovery of the quinuclidinyl N-methoxy imidoyl nitrile R-(+)-(Z)-5g which is a functionally selective muscarinic M1 partial agonist currently in phase III clinical trials for the treatment of SDAT. The selective profile of R-(+)-(Z)-5g can be rationalized in terms of the relative affinity of the compound at muscarinic receptor subtypes, the degree of agonist efficacy, and brain penetrancy.
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Loudon JM, Bromidge SM, Brown F, Clark MS, Hatcher JP, Hawkins J, Riley GJ, Noy G, Orlek BS. SB 202026: a novel muscarinic partial agonist with functional selectivity for M1 receptors. J Pharmacol Exp Ther 1997; 283:1059-68. [PMID: 9399977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The finding that ascending cholinergic systems are severely degenerated in Alzheimer's disease has driven the search for a cholinomimetic therapy. Adverse effects observed with cholinesterase inhibitors and high-efficacy muscarinic agonists led us to design compounds with an improved profile. SB 202026 (R-(Z)-(+)-alpha-(methoxyimino)-1-azabicyclo[2.2.2] octane-3-acetonitrile) displaced [3H]-oxotremorine-M from muscarinic receptors in the rat brain with high affinity (IC50 = 14 nM), a potency similar to that of oxotremorine-M itself (IC50 = 13 nM), but exhibited low affinity for cholinergic nicotinic receptors and other neuroreceptors. In studies using cloned human muscarinic receptors, SB 202026 possessed approximately equal affinity in displacing [3H]-quinuclidinyl benzilate from all muscarinic receptor subtypes. In functional models in vitro, SB 202026 caused maximal depolarization of the rat superior cervical ganglion at low concentrations (300 nM) (M1-mediated effect), while producing a lower maximal effect than the high-efficacy agonists oxotremorine-M and carbachol on M2-mediated release of ACh and M3-mediated smooth muscle contraction (guinea pig ileum), respectively. The functional selectivity and partial agonist profile seen in vitro were reflected in vivo through potent cognition-related activity (M1-induced increase in hippocampal EEG power) combined with low efficacy, compared with arecoline or oxotremorine, on induction of bradycardia (M2-mediated response), hypotension (via M3-mediated vasorelaxation) and tremor (thought to be mediated by M3 receptors). The foregoing profile of SB 202026 predicted that cognition-enhancing activity would be achieved at doses below those that initiate undesirable side effects, and this has subsequently been demonstrated in rodents, marmosets and humans.
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Hawkins J. New ruling finalizes IRS position on physician recruitment incentives. MEDICAL NETWORK STRATEGY REPORT 1997; 6:8-9. [PMID: 10167821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Petryshen P, Stevens B, Hawkins J, Stewart M. Comparing nursing costs for preterm infants receiving conventional vs. developmental care. NURSING ECONOMIC$ 1997; 15:138-45, 150. [PMID: 9305114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The incremental costs incurred by VLBW (less than 1,500 grams) infants during the first year of life accounted for one-third of the $11.4 billion spent in the U.S. on health care. Developmental care for VLBW infants focuses on light and noise management, coordination of interventions to minimize sleep interruptions and positioning/bundling the infant to prevent disorganizaiton and promote self-regulation. When compared to 60 VLBW infants receiving conventional NICU care, improved physiologic stability measures and fewer days in the NICU were recorded for the 60 VLBW infants cared for by nurses and trained developmental care specialists. Because the move from the NICU to the transitional unit occurred earlier for the developmental group of VLBW infants, and their nursing intensity needs were lower, the average cost savings achieved for this group was $4,340 per infant during the first 35 days of life or less if discharged.
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LoGrasso PV, Hawkins J, Frank LJ, Wisniewski D, Marcy A. Mechanism of activation for Zap-70 catalytic activity. Proc Natl Acad Sci U S A 1996; 93:12165-70. [PMID: 8901551 PMCID: PMC37961 DOI: 10.1073/pnas.93.22.12165] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
There is a growing body of evidence, including data from human genetic and T-cell receptor function studies, which implicate a zeta-associated protein of M(r) 70,000 (Zap-70) as a critical protein tyrosine kinase in T-cell activation and development. During T-cell activation, Zap-70 becomes associated via its src homology type 2 (SH2) domains with tyrosine-phosphorylated immune-receptor tyrosine activating motif (ITAM) sequences in the cytoplasmic zeta chain of the T-cell receptor. An intriguing conundrum is how Zap-70 is catalytically activated for downstream phosphorylation events. To address this question, we have used purified Zap-70, tyrosine phosphorylated glutathione S-transferase (GST)-Zeta, and GST-Zeta-1 cytoplasmic domains, and various forms of ITAM-containing peptides to see what effect binding of zeta had upon Zap-70 tyrosine kinase activity. The catalytic activity of Zap-70 with respect to autophosphorylation increased approximately 5-fold in the presence of 125 nM phosphorylated GST-Zeta or GST-Zeta-1 cytoplasmic domain. A 20-fold activity increase was observed for phosphorylation of an exogenous substrate. Both activity increases showed a GST-Zeta concentration dependence. The increase in activity was not produced with nonphosphorylated GST-Zeta, phosphorylated zeta, or phosphorylated ITAM-containing peptides. The increase in Zap-70 activity was SH2 mediated and was inhibited by phenylphosphate, Zap-70 SH2, and an antibody specific for Zap-70 SH2 domains. Since GST-Zeta and GST-Zeta-1 exist as dimers, the data suggest Zap-70 is activated upon binding a dimeric form of phosphorylated zeta and not by peptide fragments containing a single phosphorylated ITAM. Taken together, these data indicate that the catalytic activity of Zap-70 is most likely activated by a trans-phosphorylation mechanism.
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Hawkins J. Managed care calls for new physician compensation formulas. MEDICAL NETWORK STRATEGY REPORT 1996; 5:7-9. [PMID: 10161626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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